U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Autistic behavior

MedGen UID:
163547
Concept ID:
C0856975
Mental or Behavioral Dysfunction
Synonym: Autistic behaviors
 
HPO: HP:0000729

Definition

Persistent deficits in social interaction and communication and interaction as well as a markedly restricted repertoire of activity and interest as well as repetitive patterns of behavior. [from HPO]

Conditions with this feature

Rett syndrome
MedGen UID:
48441
Concept ID:
C0035372
Disease or Syndrome
The spectrum of MECP2-related phenotypes in females ranges from classic Rett syndrome to variant Rett syndrome with a broader clinical phenotype (either milder or more severe than classic Rett syndrome) to mild learning disabilities; the spectrum in males ranges from severe neonatal encephalopathy to pyramidal signs, parkinsonism, and macroorchidism (PPM-X) syndrome to severe syndromic/nonsyndromic intellectual disability. Females: Classic Rett syndrome, a progressive neurodevelopmental disorder primarily affecting girls, is characterized by apparently normal psychomotor development during the first six to 18 months of life, followed by a short period of developmental stagnation, then rapid regression in language and motor skills, followed by long-term stability. During the phase of rapid regression, repetitive, stereotypic hand movements replace purposeful hand use. Additional findings include fits of screaming and inconsolable crying, autistic features, panic-like attacks, bruxism, episodic apnea and/or hyperpnea, gait ataxia and apraxia, tremors, seizures, and acquired microcephaly. Males: Severe neonatal-onset encephalopathy, the most common phenotype in affected males, is characterized by a relentless clinical course that follows a metabolic-degenerative type of pattern, abnormal tone, involuntary movements, severe seizures, and breathing abnormalities. Death often occurs before age two years.
Cohen syndrome
MedGen UID:
78539
Concept ID:
C0265223
Congenital Abnormality
Cohen syndrome is characterized by failure to thrive in infancy and childhood; truncal obesity in the teen years; early-onset hypotonia and developmental delays; microcephaly developing during the first year of life; moderate to profound psychomotor retardation; progressive retinochoroidal dystrophy and high myopia; neutropenia in many with recurrent infections and aphthous ulcers in some; a cheerful disposition; joint hypermobility; and characteristic facial features.
Proline dehydrogenase deficiency
MedGen UID:
120645
Concept ID:
C0268529
Disease or Syndrome
Phang et al. (2001) noted that prospective studies of HPI probands identified through newborn screening as well as reports of several families have suggested that it is a metabolic disorder not clearly associated with clinical manifestations. Phang et al. (2001) concluded that HPI is a relatively benign condition in most individuals under most circumstances. However, other reports have suggested that some patients have a severe phenotype with neurologic manifestations, including epilepsy and mental retardation (Jacquet et al., 2003). Genetic Heterogeneity of Hyperprolinemia See also hyperprolinemia type II (HYRPRO2; 239510), which is caused by mutation in the gene encoding pyrroline-5-carboxylate dehydrogenase (P5CDH, ALDH4A1; 606811) on chromosome 1p36.
Landau-Kleffner syndrome
MedGen UID:
79465
Concept ID:
C0282512
Disease or Syndrome
GRIN2A-related speech disorders and epilepsy are characterized by speech disorders in all affected individuals and a range of epilepsy syndromes present in about 90%. Severe speech disorders observed can include dysarthria and speech dyspraxia, and both receptive and expressive language delay/regression; more mildly affected individuals may display subtly impaired intelligibility of conversational speech. Epilepsy features include seizure onset usually between ages three and six years, focal epilepsy with language and/or global developmental regression, and electroencephalogram (EEG) showing continuous spike-and-wave discharges in sleep or very active centrotemporal discharges. Seizure types include seizures associated with aura of perioral paresthesia, focal or focal motor seizures (often evolving to generalized tonic-clonic), and atypical absence seizures. Epilepsy syndromes can include: Landau-Kleffner syndrome (LKS), epileptic encephalopathy with continuous spike-and-wave during sleep (ECSWS), childhood epilepsy with centrotemporal spikes (CECTS), atypical childhood epilepsy with centrotemporal spikes (ACECTS), autosomal dominant rolandic epilepsy with speech dyspraxia (ADRESD), and infantile-onset epileptic encephalopathy.
Myoclonic-astatic epilepsy
MedGen UID:
98284
Concept ID:
C0393702
Disease or Syndrome
A generalized myoclonic-atonic seizure is a type of generalized motor seizure characterized by a myoclonic jerk followed by an atonic motor component.
Leukocyte adhesion deficiency type II
MedGen UID:
96022
Concept ID:
C0398739
Disease or Syndrome
Congenital disorder of glycosylation type IIc (CDG2C) is an autosomal recessive disorder characterized by moderate to severe psychomotor retardation, mild dysmorphism, and impaired neutrophil motility. It is a member of a group of disorders with a defect in the processing of protein-bound glycans. For a general overview of congenital disorders of glycosylation (CDGs), see CDG1A (212065) and CDG2A (212066). Frydman (1996) contended that the neutrophil defect in CDG2C, which has been referred to as 'leukocyte adhesion deficiency type II' (LAD2), is a manifestation of the disorder and that there are no cases of 'primary' LAD II. Etzioni and Harlan (1999) provided a comprehensive review of both leukocyte adhesion deficiency-1 (LAD1; 116920) and LAD2. While the functional neutrophil studies are similar in the 2 LADs, the clinical course is milder in LAD2. Furthermore, patients with LAD2 present other abnormal features, such as growth and mental retardation, which are related to the primary defect in fucose metabolism. Delayed separation of the umbilical cord occurs in LAD1. For a discussion of genetic heterogeneity of LAD, see 116920.
Microphthalmia, syndromic 1
MedGen UID:
162898
Concept ID:
C0796016
Congenital Abnormality
Microphthalmia-ankyloblepharon-intellectual disability syndrome is characterized by microphthalmia, ankyloblepharon and intellectual deficit. It has been described in seven male patients from two generations of a Northern Ireland family. The causative gene is localized to the Xq27-q28 region. The syndrome is transmitted as an X-linked recessive trait.
Intellectual disability, X-linked 49
MedGen UID:
923000
Concept ID:
C0796221
Disease or Syndrome
CLCN4-related neurodevelopmental disorder (CLCN4-NDD), an X-linked disorder, is characterized in the 36 males reported to date by developmental delay or intellectual disability, behavioral/mental health issues (e.g., autism spectrum disorder, anxiety, hyperactivity, and bipolar disorder), epilepsy, and gastrointestinal dysfunction. The five heterozygous females with a de novo CLCN4 variant reported to date had findings very similar to those of affected males. Twenty-two of 25 heterozygous females identified in family studies following identification of an affected male were unaffected or had only mild specific learning difficulties and/or mental health concerns, whereas three were more severely affected.
X-linked intellectual disability-psychosis-macroorchidism syndrome
MedGen UID:
163232
Concept ID:
C0796222
Disease or Syndrome
The spectrum of MECP2-related phenotypes in females ranges from classic Rett syndrome to variant Rett syndrome with a broader clinical phenotype (either milder or more severe than classic Rett syndrome) to mild learning disabilities; the spectrum in males ranges from severe neonatal encephalopathy to pyramidal signs, parkinsonism, and macroorchidism (PPM-X) syndrome to severe syndromic/nonsyndromic intellectual disability. Females: Classic Rett syndrome, a progressive neurodevelopmental disorder primarily affecting girls, is characterized by apparently normal psychomotor development during the first six to 18 months of life, followed by a short period of developmental stagnation, then rapid regression in language and motor skills, followed by long-term stability. During the phase of rapid regression, repetitive, stereotypic hand movements replace purposeful hand use. Additional findings include fits of screaming and inconsolable crying, autistic features, panic-like attacks, bruxism, episodic apnea and/or hyperpnea, gait ataxia and apraxia, tremors, seizures, and acquired microcephaly. Males: Severe neonatal-onset encephalopathy, the most common phenotype in affected males, is characterized by a relentless clinical course that follows a metabolic-degenerative type of pattern, abnormal tone, involuntary movements, severe seizures, and breathing abnormalities. Death often occurs before age two years.
Cerebellar ataxia-areflexia-pes cavus-optic atrophy-sensorineural hearing loss syndrome
MedGen UID:
318633
Concept ID:
C1832466
Disease or Syndrome
ATP1A3-related neurologic disorders represent a clinical continuum in which at least three distinct phenotypes have been delineated: rapid-onset dystonia-parkinsonism (RDP); alternating hemiplegia of childhood (ACH); and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS). However, some affected individuals have intermediate phenotypes or only a few features that do not fit well into one of these major phenotypes. RDP has been characterized by: abrupt onset of dystonia over days to weeks with parkinsonism (primarily bradykinesia and postural instability); common bulbar involvement; and absence or minimal response to an adequate trial of L-dopa therapy, with few exceptions. Often fever, physiologic stress, or alcoholic binges trigger the onset of symptoms. After their initial appearance, symptoms often stabilize with little improvement; occasionally second episodes occur with abrupt worsening of symptoms. Rarely, affected individuals have reported a more gradual onset of symptoms over weeks to months. Anxiety, depression, and seizures have been reported. Age of onset ranges from four to 55 years, although a childhood variation of RDP with onset between ages nine and 14 months has been reported. AHC is a complex neurodevelopmental syndrome most frequently manifesting in infancy or early childhood with paroxysmal episodic neurologic dysfunction including alternating hemiparesis or dystonia, quadriparesis, seizure-like episodes, and oculomotor abnormalities. Episodes can last for minutes, hours, days, or even weeks. Remission of symptoms occurs with sleep and immediately after awakening. Over time, persistent neurologic deficits including oculomotor apraxia, ataxia, choreoathetosis, dystonia, parkinsonism, and cognitive and behavioral dysfunction develop in the majority of those affected; more than 50% develop epilepsy in addition to their episodic movement disorder phenotype. CAPOS (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) syndrome is characterized by episodes of ataxic encephalopathy and/or weakness during and after a febrile illness. Onset is between ages six months and four years. Some acute symptoms resolve; progression of sensory losses and severity vary.
Cardiac malformation, cleft lip/palate, microcephaly, and digital anomalies
MedGen UID:
318752
Concept ID:
C1832950
Disease or Syndrome
Intellectual disability, X-linked 82
MedGen UID:
337201
Concept ID:
C1845286
Mental or Behavioral Dysfunction
Autism, susceptibility to, X-linked 2
MedGen UID:
336964
Concept ID:
C1845539
Finding
Autism, the prototypic pervasive developmental disorder (PDD), is usually apparent by 3 years of age. It is characterized by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypic, and ritualized patterns of interests and behavior (Bailey et al., 1996; Risch et al., 1999). 'Autism spectrum disorder,' sometimes referred to as ASD, is a broader phenotype encompassing the less severe disorders Asperger syndrome (see ASPG1; 608638) and pervasive developmental disorder, not otherwise specified (PDD-NOS). 'Broad autism phenotype' includes individuals with some symptoms of autism, but who do not meet the full criteria for autism or other disorders. Impaired intellectual development coexists in approximately two-thirds of individuals with ASD, except for Asperger syndrome, in which intellectual disability is conspicuously absent (Jones et al., 2008). Genetic studies in autism often include family members with these less stringent diagnoses (Schellenberg et al., 2006). For a discussion of genetic heterogeneity of autism, see 209850.
Intellectual disability, X-linked 63
MedGen UID:
337002
Concept ID:
C1845672
Mental or Behavioral Dysfunction
Any non-syndromic X-linked intellectual disability in which the cause of the disease is a mutation in the ACSL4 gene.
Intellectual disability, X-linked 72
MedGen UID:
375793
Concept ID:
C1846038
Mental or Behavioral Dysfunction
Syndromic X-linked intellectual disability Lubs type
MedGen UID:
337496
Concept ID:
C1846058
Disease or Syndrome
MECP2 duplication syndrome is a severe neurodevelopmental disorder characterized by early-onset hypotonia, feeding difficulty, gastrointestinal manifestations including gastroesophageal reflux and constipation, delayed psychomotor development leading to severe intellectual disability, poor speech development, progressive spasticity, recurrent respiratory infections (in ~75% of affected individuals), and seizures (in ~50%). MECP2 duplication syndrome is 100% penetrant in males. Occasionally females have been described with a MECP2 duplication and a range of findings from mild intellectual disability to a phenotype similar to that seen in males. In addition to the core features, autistic behaviors, nonspecific neuroradiologic findings on brain MRI, mottled skin, and urogenital anomalies have been observed in several affected boys.
Developmental and epileptic encephalopathy, 9
MedGen UID:
338393
Concept ID:
C1848137
Disease or Syndrome
Developmental and epileptic encephalopathy-9 (DEE9) is an X-linked disorder characterized by seizure onset in infancy and mild to severe intellectual impairment. Autistic and psychiatric features have been reported in some individuals. The disorder affects heterozygous females only; transmitting males are unaffected (summary by Jamal et al., 2010). For a general phenotypic description and a discussion of genetic heterogeneity of developmental and epileptic encephalopathy, see 308350.
Saldino-Mainzer syndrome
MedGen UID:
341455
Concept ID:
C1849437
Disease or Syndrome
Short-rib thoracic dysplasia (SRTD) with or without polydactyly refers to a group of autosomal recessive skeletal ciliopathies that are characterized by a constricted thoracic cage, short ribs, shortened tubular bones, and a 'trident' appearance of the acetabular roof. SRTD encompasses Ellis-van Creveld syndrome (EVC) and the disorders previously designated as Jeune syndrome or asphyxiating thoracic dystrophy (ATD), short rib-polydactyly syndrome (SRPS), and Mainzer-Saldino syndrome (MZSDS). Polydactyly is variably present, and there is phenotypic overlap in the various forms of SRTDs, which differ by visceral malformation and metaphyseal appearance. Nonskeletal involvement can include cleft lip/palate as well as anomalies of major organs such as the brain, eye, heart, kidneys, liver, pancreas, intestines, and genitalia. Some forms of SRTD are lethal in the neonatal period due to respiratory insufficiency secondary to a severely restricted thoracic cage, whereas others are compatible with life (summary by Huber and Cormier-Daire, 2012 and Schmidts et al., 2013). There is phenotypic overlap with the cranioectodermal dysplasias (Sensenbrenner syndrome; see CED1, 218330). For a discussion of genetic heterogeneity of short-rib thoracic dysplasia, see SRTD1 (208500).
Tuberous sclerosis 1
MedGen UID:
344288
Concept ID:
C1854465
Disease or Syndrome
Tuberous sclerosis complex (TSC) involves abnormalities of the skin (hypomelanotic macules, confetti skin lesions, facial angiofibromas, shagreen patches, fibrous cephalic plaques, ungual fibromas); brain (subependymal nodules, cortical tubers, and subependymal giant cell astrocytomas [SEGAs], seizures, intellectual disability / developmental delay, psychiatric illness); kidney (angiomyolipomas, cysts, renal cell carcinomas); heart (rhabdomyomas, arrhythmias); and lungs (lymphangioleiomyomatosis [LAM], multifocal micronodular pneumonocyte hyperplasia). Central nervous system tumors are the leading cause of morbidity and mortality; renal disease is the second leading cause of early death.
7q11.23 microduplication syndrome
MedGen UID:
347562
Concept ID:
C1857844
Disease or Syndrome
7q11.23 duplication syndrome is characterized by delayed motor, speech, and social skills in early childhood; neurologic abnormalities (hypotonia, adventitious movements, and abnormal gait and station); speech sound disorders including motor speech disorders (childhood apraxia of speech and/or dysarthria) and phonologic disorders; behavior problems including anxiety disorders (especially social anxiety disorder [social phobia]), selective mutism, attention-deficit/hyperactivity disorder, oppositional disorders, physical aggression, and autism spectrum disorder; and intellectual disability in some individuals. Distinctive facial features are common. Cardiovascular disease includes dilatation of the ascending aorta. Approximately 30% of individuals have one or more congenital anomalies.
Intellectual disability, autosomal dominant 1
MedGen UID:
409857
Concept ID:
C1969562
Mental or Behavioral Dysfunction
MBD5 haploinsufficiency is a neurodevelopmental disorder characterized by developmental delay, intellectual disability, severe speech impairment, seizures, sleep disturbances, and abnormal behaviors. Most children lack speech entirely or have single words, short phrases, or short sentences. Seizures are present in more than 80% of children; onset is usually around age two years. Sleep disturbances, present in about 90%, can result in excessive daytime drowsiness. Abnormal behaviors can include autistic-like behaviors (80%) and self-injury and aggression (>60%).
Syndromic X-linked intellectual disability 14
MedGen UID:
372646
Concept ID:
C1970822
Disease or Syndrome
Any X-linked syndromic intellectual disability in which the cause of the disease is a mutation in the UPF3B gene.
Intellectual disability, autosomal dominant 5
MedGen UID:
382611
Concept ID:
C2675473
Mental or Behavioral Dysfunction
SYNGAP1-related intellectual disability (SYNGAP1-ID) is characterized by developmental delay (DD) or intellectual disability (ID) (100% of affected individuals), generalized epilepsy (~84%), and autism spectrum disorder (ASD) and other behavioral abnormalities (=50%). To date more than 50 individuals with SYNGAP1-ID have been reported. In the majority DD/ID was moderate to severe; in some it was mild. The epilepsy is generalized; a subset of individuals with epilepsy have myoclonic astatic epilepsy (Doose syndrome) or epilepsy with myoclonic absences. Behavioral abnormalities can include stereotypic behaviors (e.g., hand flapping, obsessions with certain objects) as well as poor social development. Feeding difficulties can be significant in some.
Intellectual disability, autosomal dominant 3
MedGen UID:
436447
Concept ID:
C2675488
Mental or Behavioral Dysfunction
Any autosomal dominant non-syndromic intellectual disability in which the cause of the disease is a mutation in the CDH15 gene.
Chromosome 2p16.1-p15 deletion syndrome
MedGen UID:
390902
Concept ID:
C2675875
Disease or Syndrome
Chromosome 2p16.1-p15 deletion syndrome is a neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, and variable but distinctive dysmorphic features, including microcephaly, bitemporal narrowing, smooth and long philtrum, hypertelorism, downslanting palpebral fissures, broad nasal root, thin upper lip, and high palate. Many patients have behavioral disorders, including autistic features, as well as structural brain abnormalities, such as pachygyria or hypoplastic corpus callosum. Those with deletions including the BCL11A gene (606557) also have persistence of fetal hemoglobin (HbF), which is asymptomatic and does not affected hematologic parameters or susceptibility to infection (summary by Funnell et al., 2015). Point mutation in the BCL11A gene causes intellectual developmental disorder with persistence of fetal hemoglobin (617101), which shows overlapping features. See also fetal hemoglobin quantitative trait locus-5 (HBFQTL5; 142335).
Wilms tumor, aniridia, genitourinary anomalies, intellectual disability, and obesity syndrome
MedGen UID:
382718
Concept ID:
C2675904
Disease or Syndrome
For a detailed discussion of the WAGR syndrome, see 194072. In a subgroup of individuals with the WAGR syndrome, obesity develops. The phenotype in this subset is associated with haploinsufficiency for the BDNF gene.
Syndromic X-linked intellectual disability 94
MedGen UID:
437111
Concept ID:
C2678051
Disease or Syndrome
A syndromic X-linked intellectual disability characterized by moderate intellectual disability with variable occurrence of asthenic body habitus, dysmorphic features, autistic features, macrocephaly, seizures, myoclonic jerks, and hyporeflexia that has material basis in mutation in the GRIA3 gene on chromosome Xq25.
Intellectual disability, X-linked 97
MedGen UID:
440689
Concept ID:
C2749020
Mental or Behavioral Dysfunction
Any non-syndromic X-linked intellectual disability in which the cause of the disease is a mutation in the ZNF711 gene.
Cortical dysplasia-focal epilepsy syndrome
MedGen UID:
413258
Concept ID:
C2750246
Disease or Syndrome
Pitt-Hopkins-like syndrome-1 (PTHSL1) is an autosomal recessive neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, severe speech impairment or regression, and behavioral abnormalities. Most patients have onset of seizures within the first years of life. Some patients may have cortical dysplasia on brain imaging (summary by Smogavec et al., 2016).
Clark-Baraitser syndrome
MedGen UID:
443983
Concept ID:
C2931130
Disease or Syndrome
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by intellectual disability, obesity, macrocephaly, behavioral abnormalities (such as aggressive tantrums and autistic-like behavior), and delayed speech development. Dysmorphic facial features include large, square forehead, prominent supraorbital ridges, broad nasal tip, large ears, prominent lower lip, and minor dental anomalies such as small upper lateral incisors and central incisor gap.
Intellectual disability, X-linked 1
MedGen UID:
444070
Concept ID:
C2931498
Mental or Behavioral Dysfunction
An X-linked dominant condition caused by mutation(s) in the IQSEC2 gene, encoding IQ motif and SEC7 domain-containing protein 2. It is characterized by substantially impaired intellectual functioning and behavioral abnormalities.
Chromosome 2q37 deletion syndrome
MedGen UID:
419169
Concept ID:
C2931817
Disease or Syndrome
Patients with chromosome 2q37 deletion syndrome show highly variable clinical manifestations likely resulting from different deletion sizes and deletions of different genes. Variable clinical features included brachydactyly type E (BDE), affecting the metacarpals and metatarsals (in about 50% of patients), short stature, mild to moderate intellectual disability, behavioral abnormalities, and dysmorphic facial features. However, many individuals with deletions do not show cognitive deficits (summary by Villavicencio-Lorini et al., 2013, Wheeler et al., 2014, Jean-Marcais et al., 2015).
Chromosome 16p13.3 duplication syndrome
MedGen UID:
462058
Concept ID:
C3150708
Disease or Syndrome
16p13.3 microduplication syndrome is a rare chromosomal anomaly syndrome resulting from a partial duplication of the short arm of chromosome 16 and manifesting with a variable phenotype which is mostly characterized by: mild to moderate intellectual deficit and developmental delay (particularly speech), normal growth, short, proximally implanted thumbs and other hand and feet malformations (such as camptodactyly, syndactyly, club feet), mild arthrogryposis and characteristic facies (upslanting, narrow palpebral fissures, hypertelorism, mid face hypoplasia, bulbous nasal tip and low set ears). Other reported manifestations include cryptorchidism, inguinal hernia and behavioral problems.
Chromosome 4Q32.1-q32.2 triplication syndrome
MedGen UID:
462207
Concept ID:
C3150857
Disease or Syndrome
Rubinstein-Taybi syndrome due to EP300 haploinsufficiency
MedGen UID:
462291
Concept ID:
C3150941
Disease or Syndrome
Rubinstein-Taybi syndrome (RSTS) is characterized by distinctive facial features, broad and often angulated thumbs and halluces, short stature, and moderate-to-severe intellectual disability. The characteristic craniofacial features are downslanted palpebral fissures, low-hanging columella, high palate, grimacing smile, and talon cusps. Prenatal growth is often normal, then height, weight, and head circumference percentiles rapidly drop in the first few months of life. Short stature is typical in adulthood. Obesity may develop in childhood or adolescence. Average IQ ranges between 35 and 50; however, developmental outcome varies considerably. Some individuals with EP300-RSTS have normal intellect. Additional features include ocular abnormalities, hearing loss, respiratory difficulties, congenital heart defects, renal abnormalities, cryptorchidism, feeding problems, recurrent infections, and severe constipation.
Obesity, hyperphagia, and developmental delay
MedGen UID:
462653
Concept ID:
C3151303
Disease or Syndrome
OBHD is a neurodevelopmental disorder characterized by global developmental delay and hyperphagia resulting in obesity. Some patients may develop seizures (summary by Hamdan et al., 2017).
Chromosome 15q11.2 deletion syndrome
MedGen UID:
467404
Concept ID:
C3180937
Disease or Syndrome
A heterozygous deletion of chromosome 15q11.2 may increase the susceptibility to neuropsychiatric or neurodevelopmental problems, including delayed psychomotor development, speech delay, autism spectrum disorder, attention deficit-hyperactivity disorder, obsessive-compulsive disorder, and possibly seizures (summary by Doornbos et al., 2009 and Burnside et al., 2011). See also chromosome 15q11.2 duplication syndrome (608636).
Rafiq syndrome
MedGen UID:
481757
Concept ID:
C3280127
Disease or Syndrome
Rafiq syndrome (RAFQS) is an autosomal recessive disorder characterized by variably impaired intellectual and motor development, a characteristic facial dysmorphism, truncal obesity, and hypotonia. The facial dysmorphism comprises prominent eyebrows with lateral thinning, downward-slanting palpebral fissures, bulbous tip of the nose, large ears, and a thin upper lip. Behavioral problems, including overeating, verbal and physical aggression, have been reported in some cases. Serum transferrin isoelectric focusing shows a type 2 pattern (summary by Balasubramanian et al., 2019).
Chromosome 8q21.11 deletion syndrome
MedGen UID:
481861
Concept ID:
C3280231
Disease or Syndrome
The chromosome 8q21.11 deletion syndrome is characterized by impaired intellectual development and common facial dysmorphic features (summary by Palomares et al., 2011).
Developmental and epileptic encephalopathy, 13
MedGen UID:
482821
Concept ID:
C3281191
Disease or Syndrome
SCN8A-related epilepsy with encephalopathy is characterized by developmental delay, seizure onset in the first 18 months of life (mean 4 months), and intractable epilepsy characterized by multiple seizure types (generalized tonic-clonic seizures, infantile spasms, and absence and focal seizures). Epilepsy syndromes can include Lennox-Gastaut syndrome, West syndrome, and epileptic encephalopathies (e.g., Dravet syndrome). Hypotonia and movement disorders including dystonia, ataxia, and choreoathetosis are common. Psychomotor development varies from normal prior to seizure onset (with subsequent slowing or regression after seizure onset) to abnormal from birth. Intellectual disability, present in all, ranges from mild to severe (in ~50% of affected individuals). Autistic features are noted in some. Sudden unexpected death in epilepsy (SUDEP) of unknown cause has been reported in approximately 10% of published cases. To date SCN8A-related epilepsy with encephalopathy has been reported in the literature in about 50 individuals.
Coffin-Siris syndrome 1
MedGen UID:
482831
Concept ID:
C3281201
Disease or Syndrome
Coffin-Siris syndrome (CSS) is classically characterized by aplasia or hypoplasia of the distal phalanx or nail of the fifth and additional digits, developmental or cognitive delay of varying degree, distinctive facial features, hypotonia, hirsutism/hypertrichosis, and sparse scalp hair. Congenital anomalies can include malformations of the cardiac, gastrointestinal, genitourinary, and/or central nervous systems. Other findings commonly include feeding difficulties, slow growth, ophthalmologic abnormalities, and hearing impairment.
Malan overgrowth syndrome
MedGen UID:
766574
Concept ID:
C3553660
Disease or Syndrome
Malan syndrome (MALNS) is clinically characterized by overgrowth, advanced bone age, macrocephaly, and dysmorphic facial features. Patients develop marfanoid habitus, with long and slender body, very low body mass, long narrow face, and arachnodactyly, with age. Impaired intellectual development and behavior anomalies are present (summary by Martinez et al., 2015).
Branched-chain keto acid dehydrogenase kinase deficiency
MedGen UID:
766992
Concept ID:
C3554078
Disease or Syndrome
Branched-chain ketoacid dehydrogenase kinase deficiency (BCKDKD) is a neurodevelopmental disorder characterized by autism, impaired intellectual development, and microcephaly (Tangeraas et al., 2023).
Pontocerebellar hypoplasia type 7
MedGen UID:
767140
Concept ID:
C3554226
Disease or Syndrome
Pontocerebellar hypoplasia type 7 (PCH7) is a severe neurologic condition characterized by delayed psychomotor development, hypotonia, breathing abnormalities, and gonadal abnormalities (summary by Anderson et al., 2011). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1 (607596).
Severe intellectual disability-progressive spastic diplegia syndrome
MedGen UID:
767363
Concept ID:
C3554449
Disease or Syndrome
CTNNB1 neurodevelopmental disorder (CTNNB1-NDD) is characterized in all individuals by mild-to-profound cognitive impairment and in up to 39% of reported individuals by exudative vitreoretinopathy, an ophthalmologic finding consistent with familial exudative vitreoretinopathy (FEVR). Other common findings include truncal hypotonia, peripheral spasticity, dystonia, behavior problems, microcephaly, and refractive errors and strabismus. Less common features include intrauterine growth restriction, feeding difficulties, and scoliosis.
X-linked intellectual disability, Cantagrel type
MedGen UID:
813060
Concept ID:
C3806730
Disease or Syndrome
X-linked intellectual developmental disorder-98 (XLID98) is a neurodevelopmental disorder characterized by delayed psychomotor development, poor speech, behavioral abnormalities, poor overall growth, dysmorphic facial features, and often early-onset seizures. Some carrier females are unaffected, whereas other females with mutations are affected; males tend to be more severely affected than females. It is believed that the phenotypic variability and disease manifestations in female carriers results from skewed X-inactivation or cellular mosaicism (summary by de Lange et al., 2016).
Intellectual disability, X-linked 99
MedGen UID:
813076
Concept ID:
C3806746
Mental or Behavioral Dysfunction
Any non-syndromic X-linked intellectual disability in which the cause of the disease is a mutation in the USP9X gene.
Developmental and epileptic encephalopathy 94
MedGen UID:
815608
Concept ID:
C3809278
Disease or Syndrome
CHD2-related neurodevelopmental disorders are characterized by early-onset epileptic encephalopathy (i.e., refractory seizures and cognitive slowing or regression associated with frequent ongoing epileptiform activity). Seizure onset is typically between ages six months and four years. Seizure types typically include drop attacks, myoclonus, and rapid onset of multiple seizure types associated with generalized spike-wave on EEG, atonic-myoclonic-absence seizures, and clinical photosensitivity. Intellectual disability and/or autism spectrum disorders are common.
Specific language impairment 5
MedGen UID:
815813
Concept ID:
C3809483
Disease or Syndrome
Specific language impairment-5 (SLI5) is characterized by a delay in early speech acquisition and is usually associated with cerebral white matter abnormalities on brain MRI. Some individuals may show disorders in communication, consistent with autism spectrum disorder, or global developmental delay, although others ultimately show normal cognitive function. Penetrance is incomplete and expressivity is variable. This type of disorder is observed most commonly among individuals of East Asian descent (summary by Wiszniewski et al., 2013). For a phenotypic description and a discussion of genetic heterogeneity of specific language impairment, see SLI1 (602081).
Intellectual disability-feeding difficulties-developmental delay-microcephaly syndrome
MedGen UID:
816016
Concept ID:
C3809686
Mental or Behavioral Dysfunction
A rare, genetic, neurodevelopmental disorder characterized by global developmental delay, borderline to severe intellectual disability, feeding difficulties, behavioral anomalies, vision anomalies and mild facial dysmorphism. Other associated features may include microcephaly, short stature, urogenital or palatal anomalies (e.g. cleft palate), minor cardiac defects, recurrent infections or hearing loss.
Developmental delay with autism spectrum disorder and gait instability
MedGen UID:
816083
Concept ID:
C3809753
Disease or Syndrome
Developmental delay with autism spectrum disorder and gait instability is a rare, genetic, neurological disorder characterized by infant hypotonia and feeding difficulties, global development delay, mild to moderated intellectual disability, delayed independent ambulation, broad-based gait with arms upheld and flexed at the elbow with brisk walking or running, and limited language skills. Behavior patterns are highly variable and range from sociable and affectionate to autistic behavior.
Autism spectrum disorder - epilepsy - arthrogryposis syndrome
MedGen UID:
816240
Concept ID:
C3809910
Disease or Syndrome
Arthrogryposis, impaired intellectual development, and seizures (AMRS) is an autosomal recessive disorder characterized by skeletal abnormalities, including arthrogryposis, short limbs, and vertebral malformations, impaired intellectual development, and seizures consistent with early-onset epileptic encephalopathy in some patients. Other features may include cleft palate, micrognathia, posterior embryotoxon, talipes valgus, rocker-bottom feet, and dysmorphic facies (Edmondson et al., 2017; Marini et al., 2017).
Macrocephaly-developmental delay syndrome
MedGen UID:
816555
Concept ID:
C3810225
Mental or Behavioral Dysfunction
Autosomal recessive intellectual developmental disorder-41 (MRT41) is characterized by macrocephaly and global developmental delay. Some patients have seizures (Baple et al., 2014).
Intellectual disability-facial dysmorphism syndrome due to SETD5 haploinsufficiency
MedGen UID:
816736
Concept ID:
C3810406
Mental or Behavioral Dysfunction
Intellectual disability-facial dysmorphism syndrome due to SETD5 haploinsufficiency is a rare, syndromic intellectual disability characterized by intellectual disability of various severity, hypotonia, feeding difficulties, dysmorphic features, autism and behavioral issues. Growth retardation, congenital heart anomalies, gastrointestinal and genitourinary defects have been rarely associated.
Intellectual disability-severe speech delay-mild dysmorphism syndrome
MedGen UID:
862201
Concept ID:
C4013764
Mental or Behavioral Dysfunction
Intellectual developmental disorder with language impairment and with or without autistic features is a neurodevelopmental disorder characterized by global developmental delay with moderate to severe speech delay that particularly affects expressive speech. Most patients have articulation defects, but frank verbal dyspraxia is not observed. Common dysmorphic features include broad forehead, downslanting palpebral fissures, short nose with broad tip, relative macrocephaly, frontal hair upsweep, and prominent digit pads. Gross motor skills are also delayed. Some patients have autistic features and/or behavioral problems. All reported cases have occurred de novo (review by Le Fevre et al., 2013).
Autism spectrum disorder due to AUTS2 deficiency
MedGen UID:
862872
Concept ID:
C4014435
Mental or Behavioral Dysfunction
A rare genetic syndromic intellectual disability characterized by global developmental delay and borderline to severe intellectual disability, autism spectrum disorder with obsessive behavior, stereotypies, hyperactivity but frequently friendly and affable personality, feeding difficulties, short stature, muscular hypotonia, microcephaly, characteristic dysmorphic features (hypertelorism, high arched eyebrows, ptosis, deep and/or broad nasal bridge, broad/prominent nasal tip, short and/or upturned philtrum, narrow mouth, and micrognathia), and skeletal anomalies (kyphosis and/or scoliosis, arthrogryposis, slender habitus and extremities). Other clinical features may include hernias, congenital heart defects, cryptorchidism and seizures.
Developmental and epileptic encephalopathy, 24
MedGen UID:
862968
Concept ID:
C4014531
Disease or Syndrome
Developmental and epileptic encephalopathy-24 (DEE24) is a neurologic disorder characterized by onset of refractory seizures in infancy, severely impaired global development, intellectual disability, and behavioral abnormalities. Most patients have onset of variable types of seizures between 4 and 13 months of age, but earlier onset in the first days of life has also been reported. Seizures are often triggered by fever, at least initially; status epilepticus may occur (summary by Nava et al., 2014 and Marini et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
ADNP-related multiple congenital anomalies - intellectual disability - autism spectrum disorder
MedGen UID:
862975
Concept ID:
C4014538
Disease or Syndrome
ADNP-related disorder is characterized by hypotonia, severe speech and motor delay, mild-to-severe intellectual disability, and characteristic facial features (prominent forehead, high anterior hairline, wide and depressed nasal bridge, and short nose with full, upturned nasal tip) based on a cohort of 78 individuals. Features of autism spectrum disorder are common (stereotypic behavior, impaired social interaction). Other common findings include additional behavioral problems, sleep disturbance, brain abnormalities, seizures, feeding issues, gastrointestinal problems, visual dysfunction (hypermetropia, strabismus, cortical visual impairment), musculoskeletal anomalies, endocrine issues including short stature and hormonal deficiencies, cardiac and urinary tract anomalies, and hearing loss.
46,XY sex reversal 9
MedGen UID:
863566
Concept ID:
C4015129
Disease or Syndrome
Intellectual disability, autosomal dominant 29
MedGen UID:
863578
Concept ID:
C4015141
Mental or Behavioral Dysfunction
SETBP1 haploinsufficiency disorder (SETBP1-HD) is characterized by hypotonia and mild motor developmental delay; intellectual abilities ranging from normal to severe disability; speech and language disorder; behavioral problems (most commonly attention/concentration deficits and hyperactivity, impulsivity), and refractive errors and strabismus. Typically children with SETBP1-HD whose intellect is in the normal or borderline range (IQ 80-90) were diagnosed following genetic testing for behavioral problems and/or severe speech and language disorders (respectively: the inability to produce sounds in words correctly, and deficits in the understanding and/or expression of words and sentences). To date, 47 individuals with SETBP1-HD have been reported.
Luscan-Lumish syndrome
MedGen UID:
898669
Concept ID:
C4085873
Disease or Syndrome
Luscan-Lumish syndrome (LLS) is characterized by macrocephaly, intellectual disability, speech delay, low sociability, and behavioral problems. More variable features include postnatal overgrowth, obesity, advanced carpal ossification, developmental delay, and seizures (Luscan et al., 2014; Lumish et al., 2015)
Seizures-scoliosis-macrocephaly syndrome
MedGen UID:
909039
Concept ID:
C4225248
Disease or Syndrome
Seizures, scoliosis, and macrocephaly/microcephaly syndrome (SSMS) is an autosomal recessive neurodevelopmental disorder characterized by global developmental delay apparent from early infancy, impaired intellectual development, behavioral problems, poor or absent speech, seizures, dysmorphic facial features with macro- or microcephaly, and skeletal abnormalities, including scoliosis and delayed bone age. Other features may include hypotonia, gastrointestinal problems, and exostoses (summary by Gentile et al., 2019).
Cutis laxa, autosomal dominant 3
MedGen UID:
899774
Concept ID:
C4225268
Disease or Syndrome
Autosomal dominant cutis laxa-3 (ADCL3) is characterized by thin skin with visible veins and wrinkles, cataract or corneal clouding, clenched fingers, pre- and postnatal growth retardation, and moderate intellectual disability. In addition, patients exhibit a combination of muscular hypotonia with brisk muscle reflexes (Fischer-Zirnsak et al., 2015). For a general phenotypic description and discussion of genetic heterogeneity of autosomal dominant cutis laxa, see ARCL1 (123700).
Intellectual disability, autosomal dominant 39
MedGen UID:
909304
Concept ID:
C4225296
Disease or Syndrome
An autosomal dominant condition caused by mutation(s) in the MYT1L gene, encoding myelin transcription factor 1-like protein. It is characterized by intellectual disability and mild dysmorphic facial features.
Microcephaly 15, primary, autosomal recessive
MedGen UID:
895496
Concept ID:
C4225310
Disease or Syndrome
Neurodevelopmental disorder with progressive microcephaly, spasticity, and brain imaging abnormalities (NEDMISBA) is an autosomal recessive disorder characterized by a spectrum of neurologic abnormalities apparent from early infancy. Affected individuals have impaired intellectual development with poor speech, progressive microcephaly, and appendicular spasticity. Brain imaging usually shows abnormalities, including enlarged ventricles, white matter defects, and atrophy or hypoplasia of brain tissue. Some patients have a more severe phenotype with seizures, lack of developmental milestones, and early death (summary by Harel et al., 2018).
Developmental and epileptic encephalopathy, 33
MedGen UID:
897930
Concept ID:
C4225337
Disease or Syndrome
Developmental and epileptic encephalopathy-33 (DEE33) is a neurologic disorder characterized by the onset of various types of seizures in the first months of life. Affected individuals show severe global developmental delay with impaired intellectual development and poor or absent speech (summary by de Ligt et al., 2012). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Intellectual disability-microcephaly-strabismus-behavioral abnormalities syndrome
MedGen UID:
897984
Concept ID:
C4225351
Disease or Syndrome
White-Sutton syndrome is a neurodevelopmental disorder characterized by a wide spectrum of cognitive dysfunction, developmental delays (particularly in speech and language acquisition), hypotonia, autism spectrum disorder, and other behavioral problems. Additional features commonly reported include seizures, refractive errors and strabismus, hearing loss, sleep disturbance (particularly sleep apnea), feeding and gastrointestinal problems, mild genital abnormalities in males, and urinary tract involvement in both males and females.
Autosomal dominant intellectual disability-craniofacial anomalies-cardiac defects syndrome
MedGen UID:
903767
Concept ID:
C4225396
Disease or Syndrome
Arboleda-Tham syndrome (ARTHS) is an autosomal dominant disorder with the core features of impaired intellectual development, speech delay, microcephaly, cardiac anomalies, and gastrointestinal complications (summary by Kennedy et al., 2019).
Intellectual disability, X-linked, syndromic 33
MedGen UID:
895979
Concept ID:
C4225418
Disease or Syndrome
X-linked syndromic intellectual developmental disorder-33 (MRXS33) is an X-linked recessive neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, and characteristic facial features (summary by O'Rawe et al., 2015).
Intellectual disability, X-linked 61
MedGen UID:
924419
Concept ID:
C4283894
Disease or Syndrome
Tonne-Kalscheuer syndrome (TOKAS) is an X-linked recessive multiple congenital anomaly disorder with 2 main presentations. Most patients exhibit global developmental delay apparent from early infancy, impaired intellectual development, speech delay, behavioral abnormalities, and abnormal gait. Affected individuals also have dysmorphic facial features that evolve with age, anomalies of the hands, feet, and nails, and urogenital abnormalities with hypogenitalism. A subset of more severely affected males develop congenital diaphragmatic hernia in utero, which may result in perinatal or premature death. Carrier females may have very mild skeletal or hormonal abnormalities (summary by Frints et al., 2019). Also see Fryns syndrome (229850), an autosomal recessive disorder with overlapping features.
X-linked intellectual disability, van Esch type
MedGen UID:
930741
Concept ID:
C4305072
Disease or Syndrome
Van Esch-O'Driscoll syndrome (VEODS) is characterized by varying degrees of intellectual disability, moderate to severe short stature, microcephaly, hypogonadism, and variable congenital malformations (Van Esch et al., 2019).
Neurodevelopmental disorder with hypotonia, seizures, and absent language
MedGen UID:
934610
Concept ID:
C4310643
Disease or Syndrome
Lissencephaly 8
MedGen UID:
934613
Concept ID:
C4310646
Disease or Syndrome
Lissencephaly-8 (LIS8) is an autosomal recessive neurologic disorder characterized by delayed psychomotor development, intellectual disability with poor or absent speech, early-onset refractory seizures, and hypotonia. Brain imaging shows variable features, including cortical gyral abnormalities and hypoplasia of the corpus callosum, brainstem, and cerebellum (Jerber et al., 2016). For a general description and a discussion of genetic heterogeneity lissencephaly, see LIS1 (607432).
Intellectual disability, autosomal recessive 57
MedGen UID:
934640
Concept ID:
C4310673
Mental or Behavioral Dysfunction
Any autosomal recessive non-syndromic intellectual disability in which the cause of the disease is a mutation in the MBOAT7 gene.
ZTTK syndrome
MedGen UID:
934663
Concept ID:
C4310696
Disease or Syndrome
ZTTK syndrome (ZTTKS) is a severe multisystem developmental disorder characterized by delayed psychomotor development and intellectual disability. Affected individuals have characteristic dysmorphic facial features, hypotonia, poor feeding, poor overall growth, and eye or visual abnormalities. Most patients also have musculoskeletal abnormalities, and some have congenital defects of the heart and urogenital system. Brain imaging usually shows developmental abnormalities such as gyral changes, cortical and/or cerebellar atrophy, and thin corpus callosum (summary by Kim et al., 2016).
Micrognathia-recurrent infections-behavioral abnormalities-mild intellectual disability syndrome
MedGen UID:
934707
Concept ID:
C4310740
Disease or Syndrome
TRIO-related intellectual disability (ID) is characterized by delay in acquisition of motor and language skills, mild to borderline intellectual disability, and neurobehavioral problems (including autistic traits or autism spectrum disorder, attention-deficit/hyperactivity disorder, and/or aggression). Neonatal or infantile feeding difficulties including poor suck, impaired bottle feeding, and failure to thrive are common and are often the presenting finding. Other findings can include microcephaly, variable hand and dental abnormalities, and suggestive facial features. Only ten of the 20 individuals with a TRIO pathogenic variant reported to date had sufficient information to make preliminary generalizations about clinical manifestations; it is anticipated that the phenotype of this newly described disorder will continue to evolve.
Intellectual disability, autosomal dominant 43
MedGen UID:
934738
Concept ID:
C4310771
Mental or Behavioral Dysfunction
HIVEP2-related intellectual disability is a neurological disorder characterized by moderate to severe developmental delay and intellectual disability and mild physical abnormalities (dysmorphic features). Early symptoms of the condition include weak muscle tone (hypotonia) and delayed development of motor skills, such as sitting, standing, and walking. After learning to walk, many affected individuals continue to have difficulty with this activity; their walking style (gait) is often unbalanced and wide-based. Speech is also delayed, and some people with this condition never learn to talk. Most people with HIVEP2-related intellectual disability also have unusual physical features, such as widely spaced eyes (hypertelorism), a broad nasal bridge, or fingers with tapered ends, although there is no characteristic pattern of such features among affected individuals. Many people with the condition exhibit neurodevelopmental disorders, such as hyperactivity, attention deficit disorder, aggression, anxiety, and autism spectrum disorder, which is a group of developmental disorders characterized by impaired communication and social interaction.\n\nOther features of HIVEP2-related intellectual disability include mild abnormalities in the structure of the brain and an abnormally small brain and head size (microcephaly). Less common health problems include seizures; recurrent ear infections; and eye disorders, such as eyes that do not look in the same direction (strabismus), "lazy eye" (amblyopia), and farsightedness (hyperopia). Some people with HIVEP2-related intellectual disability have gastrointestinal problems, which can include backflow of acidic stomach contents into the esophagus (gastroesophageal reflux) and constipation.
Neurodevelopmental disorder with or without anomalies of the brain, eye, or heart
MedGen UID:
934739
Concept ID:
C4310772
Disease or Syndrome
RERE-related disorders are characterized by neurodevelopmental problems with or without structural anomalies of the eyes, heart, kidneys, and genitourinary tract and mild sensorineural hearing loss. Hypotonia and feeding problems are common among affected individuals. Developmental delay and intellectual disability range from mild to profound. Behavior problems may include attention-deficit/hyperactivity disorder, self-injurious behavior, and autism spectrum disorder. A variety of eye anomalies (coloboma, optic nerve anomalies, microphthalmia, and/or Peter's anomaly) and vision issues (myopia, anisometropia, astigmatism, exotropia, esotropia) have been reported. Congenital heart defects, most commonly septal defects, have also been described. Genitourinary abnormalities include vesicoureteral reflux, and cryptorchidism and hypospadias in males. Sensorineural hearing loss can be unilateral or bilateral.
Intellectual disability, autosomal dominant 41
MedGen UID:
934751
Concept ID:
C4310784
Disease or Syndrome
Any autosomal dominant non-syndromic intellectual disability in which the cause of the disease is a mutation in the TBL1XR1 gene.
SIN3A-related intellectual disability syndrome due to a point mutation
MedGen UID:
934771
Concept ID:
C4310804
Disease or Syndrome
Witteveen-Kolk syndrome (WITKOS) is an autosomal dominant disorder with characteristic distinctive facial features, microcephaly, short stature, and mildly impaired intellectual development with delayed cognitive and motor development and subtle anomalies on MRI-brain imaging (summary by Balasubramanian et al., 2021).
Intellectual disability, X-linked, syndromic, Bain type
MedGen UID:
934781
Concept ID:
C4310814
Disease or Syndrome
Most individuals with HNRNPH2-related neurodevelopmental disorder (HNRNPH2-NDD) have symptoms early in life, before age 12 months. The major features of HNRNPH2-NDD are developmental delay / intellectual disability, motor and language delays, behavioral and psychiatric disorders, and growth and musculoskeletal abnormalities. Minor features include dysmorphic facies, gastrointestinal disturbances, epilepsy, and visual defects. Although HNRNPH2-NDD is an X-linked condition, there is not enough information on affected females versus affected males to make any generalizations about phenotypic differences between the two sexes.
Intellectual disability, X-linked 104
MedGen UID:
934784
Concept ID:
C4310817
Disease or Syndrome
Any non-syndromic X-linked intellectual disability in which the cause of the disease is a mutation in the FRMPD4 gene.
Dias-Logan syndrome
MedGen UID:
934800
Concept ID:
C4310833
Disease or Syndrome
BCL11A-related intellectual disability (BCL11A-ID) is characterized by developmental delay / intellectual disability of variable degree, neonatal hypotonia, microcephaly, distinctive but variable facial characteristics, behavior problems, and asymptomatic persistence of fetal hemoglobin. Growth delay, seizures, and autism spectrum disorder have also been reported in some affected individuals.
Xq25 microduplication syndrome
MedGen UID:
935016
Concept ID:
C4311049
Disease or Syndrome
Xq25 duplication syndrome is an X-linked neurodevelopmental disorder characterized by delayed development and intellectual disability associated with abnormal behavior and dysmorphic facial features. Additional variable features may include thin corpus callosum on brain imaging and sleep disturbances. Carrier females may be mildly affected (summary by Leroy et al., 2016).
Brachycephaly, trichomegaly, and developmental delay
MedGen UID:
1374289
Concept ID:
C4479431
Disease or Syndrome
BTDD is an autosomal dominant disorder characterized by brachycephaly, trichomegaly, and developmental delay. Although it is caused by dysfunction of the ribosome, patients do not have anemia (summary by Paolini et al., 2017).
Intellectual developmental disorder with gastrointestinal difficulties and high pain threshold
MedGen UID:
1385744
Concept ID:
C4479517
Disease or Syndrome
Jansen-de Vries syndrome (JDVS) is an autosomal dominant neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability with speech delay, and behavioral abnormalities. Most patients have variable additional features, including feeding and gastrointestinal difficulties, high pain threshold and/or hypersensitivity to sound, and dysmorphic features, including mild facial abnormalities, strabismus, and small hands and feet (summary by Jansen et al., 2017).
Intellectual developmental disorder with dysmorphic facies, seizures, and distal limb anomalies
MedGen UID:
1375601
Concept ID:
C4479520
Disease or Syndrome
IDDFSDA is an autosomal recessive severe multisystem disorder characterized by poor overall growth, developmental delay, early-onset seizures, intellectual disability, and dysmorphic features. There is phenotypic variability. The most severely affected patients have a neurodevelopmental disorder with microcephaly, absent speech, and inability to walk, and they require feeding tubes. Some patients have congenital heart defects or nonspecific abnormalities on brain imaging. Less severely affected individuals have mild to moderate intellectual disability with normal speech and motor development (summary by Santiago-Sim et al., 2017).
Stankiewicz-Isidor syndrome
MedGen UID:
1375936
Concept ID:
C4479599
Disease or Syndrome
Stankiewicz-Isidor syndrome (STISS) is a neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, behavioral disorders, mild craniofacial anomalies, and variable congenital defects of the cardiac and/or urogenital systems (summary by Kury et al., 2017).
Gabriele de Vries syndrome
MedGen UID:
1375401
Concept ID:
C4479652
Disease or Syndrome
Gabriele-de Vries syndrome is characterized by mild-to-profound developmental delay / intellectual disability (DD/ID) in all affected individuals and a wide spectrum of functional and morphologic abnormalities. Intrauterine growth restriction or low birth weight and feeding difficulties are common. Congenital brain, eye, heart, kidney, genital, and/or skeletal system anomalies have also been reported. About half of affected individuals have neurologic manifestations, including hypotonia and gait abnormalities. Behavioral issues can include attention-deficit/hyperactivity disorder, anxiety, autism or autistic behavior, and schizoaffective disorder.
Intellectual disability, autosomal dominant 45
MedGen UID:
1616472
Concept ID:
C4539848
Mental or Behavioral Dysfunction
Intellectual disability, autosomal dominant 47
MedGen UID:
1622196
Concept ID:
C4539951
Mental or Behavioral Dysfunction
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by global developmental delay, variable degrees of intellectual disability, and facial dysmorphism (including high nasal bridge, deep-set eyes, and wide mouth), often associated with feeding difficulties and/or gastroesophageal reflux. Additional reported manifestations are seizures, hypotonia, autistic features, and joint laxity. Brain imaging may show non-specific features (such as cerebral atrophy).
Pontocerebellar hypoplasia, type 11
MedGen UID:
1627627
Concept ID:
C4540164
Congenital Abnormality
Pontocerebellar hypoplasia type 11 (PCH11) is an autosomal recessive neurodevelopmental disorder characterized by severely delayed psychomotor development with impaired intellectual development and poor speech, microcephaly, dysmorphic features, and pontocerebellar hypoplasia on brain imaging. Additional features are more variable (summary by Marin-Valencia et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1 (607596).
Intellectual disability, autosomal dominant 48
MedGen UID:
1619532
Concept ID:
C4540321
Mental or Behavioral Dysfunction
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by global developmental delay and moderate to severe intellectual disability, as well as variable other manifestations, such as macro- or microcephaly, epilepsy, hypotonia, behavioral problems, stereotypic movements, and facial dysmorphism (including arched eyebrows, long palpebral fissures, prominent nasal bridge, upturned nose, dysplastic ears, and broad mouth), among others. Brain imaging may show cerebellar anomalies, hypoplastic corpus callosum, enlarged ventricles, polymicrogyria, or white matter abnormalities.
Kleefstra syndrome 2
MedGen UID:
1623903
Concept ID:
C4540395
Disease or Syndrome
Kleefstra syndrome-2 (KLEFS2) is an autosomal dominant neurodevelopmental disorder characterized by delayed psychomotor development, variable intellectual disability, and mild dysmorphic features (summary by Koemans et al., 2017). For a discussion of genetic heterogeneity of Kleefstra syndrome, see KLEFS1 (610253).
Intellectual disability, autosomal dominant 50
MedGen UID:
1616989
Concept ID:
C4540470
Mental or Behavioral Dysfunction
Autosomal dominant intellectual developmental disorder-50 with behavioral abnormalities (MRD50) is characterized by variable levels of impaired intellectual development, delayed speech and motor milestones, and behavioral abnormalities, most commonly autism spectrum disorder (ASD). Some patients may also have mild craniofacial dysmorphism, congenital cardiac anomalies, or seizures (summary by Cheng et al., 2019).
Intellectual disability, autosomal dominant 51
MedGen UID:
1625009
Concept ID:
C4540474
Mental or Behavioral Dysfunction
Intellectual disability, autosomal dominant 52
MedGen UID:
1615839
Concept ID:
C4540478
Mental or Behavioral Dysfunction
Intellectual disability, autosomal dominant 54
MedGen UID:
1614787
Concept ID:
C4540484
Mental or Behavioral Dysfunction
Neurodevelopmental disorder with severe motor impairment and absent language
MedGen UID:
1622162
Concept ID:
C4540496
Mental or Behavioral Dysfunction
NEDMIAL is a neurodevelopmental disorder characterized by delayed psychomotor development and hypotonia apparent from early infancy, resulting in feeding difficulties, ataxic gait or inability to walk, delayed or absent speech development, and impaired intellectual development, sometimes with behavioral abnormalities, such as hand-flapping. Additional common features may include sleep disorder, nonspecific dysmorphic facial features, and joint hyperlaxity (summary by Lessel et al., 2017 and Mannucci et al., 2021).
Epilepsy, familial focal, with variable foci 1
MedGen UID:
1641798
Concept ID:
C4551983
Disease or Syndrome
DEPDC5-related epilepsy encompasses a range of epilepsy syndromes, almost all of which are characterized by focal seizures, with seizure onset in a discrete area of the brain. While most individuals with DEPDC5-related epilepsy have a normal brain MRI, some have epilepsy associated with a cortical malformation, usually focal cortical dysplasia. Seizure syndromes include familial focal epilepsy with variable foci (FFEVF), autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), familial mesial temporal lobe epilepsies (FMTLE), autosomal dominant epilepsy with auditory features (ADEAF), and infantile spasms. Although psychomotor development is usually normal, intellectual disability or autism spectrum disorder has been reported in some individuals.
Intellectual disability, X-linked 107
MedGen UID:
1639885
Concept ID:
C4692652
Mental or Behavioral Dysfunction
Neurodevelopmental disorder with or without hyperkinetic movements and seizures, autosomal recessive
MedGen UID:
1646665
Concept ID:
C4693325
Disease or Syndrome
GRIN1-related neurodevelopmental disorder (GRIN1-NDD) is characterized by mild-to-profound developmental delay / intellectual disability (DD/ID) in all affected individuals. Other common manifestations are epilepsy, muscular hypotonia, movement disorders, spasticity, feeding difficulties, and behavior problems. A subset of individuals show a malformation of cortical development consisting of extensive and diffuse bilateral polymicrogyria. To date, 72 individuals with GRIN1-NDD have been reported.
Intellectual disability, autosomal dominant 55, with seizures
MedGen UID:
1635938
Concept ID:
C4693371
Disease or Syndrome
Neurodevelopmental disorder with movement abnormalities, abnormal gait, and autistic features
MedGen UID:
1647077
Concept ID:
C4693405
Disease or Syndrome
Neurodevelopmental disorder with movement abnormalities, abnormal gait, and autistic features (NEDMAGA) is characterized by infantile-onset global developmental delay with severe to profound intellectual disability, mildly delayed walking with broad-based and unsteady gait, and absence of meaningful language. Patients have features of autism, with repetitive behaviors and poor communication, but usually are socially reactive and have a happy demeanor. More variable neurologic features include mild seizures, spasticity, and peripheral neuropathy (summary by Palmer et al., 2017).
Neurodevelopmental disorder with poor language and loss of hand skills
MedGen UID:
1637031
Concept ID:
C4693546
Disease or Syndrome
NDPLHS is an autosomal dominant disorder characterized by developmental stagnation or regression apparent in the first years of life and manifest as loss of purposeful hand movements, loss of language, and intellectual disability. Additional features may include stereotypic movements, dystonia, gait abnormalities, sleep disturbances, and small hands and feet. The phenotype is reminiscent of Rett syndrome (RTT; 312750) (summary by Yoo et al., 2017).
Ververi-Brady syndrome
MedGen UID:
1647785
Concept ID:
C4693824
Disease or Syndrome
Ververi-Brady syndrome (VEBRAS) is characterized by mild developmental delay, mildly impaired intellectual development and speech delay, and mild dysmorphic facial features. Affected individuals can usually attend mainstream schools with support, and may also show autistic features (summary by Ververi et al., 2018).
Microcephaly 21, primary, autosomal recessive
MedGen UID:
1646916
Concept ID:
C4693831
Disease or Syndrome
Intellectual disability, autosomal dominant 57
MedGen UID:
1648280
Concept ID:
C4748003
Mental or Behavioral Dysfunction
MRD57 is an autosomal dominant neurodevelopmental disorder with a highly variable phenotype. Most affected individuals have delayed psychomotor development apparent in infancy or early childhood, language delay, and behavioral abnormalities. Additional features may include hypotonia, feeding problems, gastrointestinal issues, and dysmorphic facial features (summary by Reijnders et al., 2018).
Intellectual developmental disorder with or without epilepsy or cerebellar ataxia
MedGen UID:
1648354
Concept ID:
C4748041
Disease or Syndrome
Developmental and epileptic encephalopathy, 66
MedGen UID:
1648486
Concept ID:
C4748070
Disease or Syndrome
Developmental and epileptic encephalopathy-66 (DEE66) is a neurologic disorder characterized by the onset of various types of seizures in the first days or weeks of life. Most seizures have focal origins; secondary generalization is common. Seizure control is difficult at first, but may become easier with time. Affected individuals show global developmental delay with hypotonia, behavioral abnormalities, and dysmorphic features or ophthalmologic defects. Brain imaging often shows cerebellar dysgenesis. A subset of patients have extraneurologic manifestations, including hematologic and distal limb abnormalities (summary by Olson et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Intellectual developmental disorder with dysmorphic facies and behavioral abnormalities
MedGen UID:
1648498
Concept ID:
C4748135
Disease or Syndrome
Intellectual developmental disorder with speech delay, dysmorphic facies, and t-cell abnormalities
MedGen UID:
1648327
Concept ID:
C4748152
Disease or Syndrome
Any BAFopathy in which the cause of the disease is a mutation in the BCL11B gene.
Glycosylphosphatidylinositol biosynthesis defect 18
MedGen UID:
1648478
Concept ID:
C4748357
Disease or Syndrome
DEE95 is a severe autosomal recessive developmental disorder characterized by severely impaired global development, hypotonia, weakness, ataxia, coarse facial features, and intractable seizures. More variable features may include abnormalities of the hands and feet, inguinal hernia, and feeding difficulties. The disorder is part of a group of similar neurologic disorders resulting from biochemical defects in the glycosylphosphatidylinositol (GPI) biosynthetic pathway (summary by Nguyen et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350. For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
Intellectual developmental disorder with hypertelorism and distinctive facies
MedGen UID:
1648403
Concept ID:
C4748381
Disease or Syndrome
Cardiac, facial, and digital anomalies with developmental delay
MedGen UID:
1648330
Concept ID:
C4748484
Disease or Syndrome
CAFDADD is a multisystemic developmental disorder with variable cardiac and digital anomalies and facial dysmorphism. Some patients may have seizures and ocular/aural abnormalities (Tokita et al., 2018).
Cortical dysplasia, complex, with other brain malformations 9
MedGen UID:
1648399
Concept ID:
C4748540
Disease or Syndrome
Complex cortical dysplasia with other brain malformations-9 is a severe autosomal recessive disorder characterized by profoundly impaired motor and cognitive development apparent from early infancy. Affected individuals develop intractable seizures and are unable to speak or ambulate. Brain imaging shows pachygyria as well as hypogenesis of the corpus callosum and other variable brain abnormalities. The phenotype results from impaired cortical neuronal migration (summary by Schaffer et al., 2018). For a discussion of genetic heterogeneity of CDCBM, see CDCBM1 (614039).
Snijders Blok-Campeau syndrome
MedGen UID:
1648495
Concept ID:
C4748701
Disease or Syndrome
Snijders Blok-Campeau syndrome (SNIBCPS) is an autosomal dominant neurodevelopmental disorder characterized by global developmental delay with impaired intellectual development and delayed speech acquisition. Affected individuals tend to have expressive language deficits, with speech apraxia and dysarthria. Other features include macrocephaly and characteristic facial features, such as prominent forehead and hypertelorism, hypotonia, and joint laxity. The severity of the neurologic deficits and presence of nonneurologic features is variable (summary by Snijders Blok et al., 2018).
Intellectual disability, autosomal recessive 66
MedGen UID:
1648460
Concept ID:
C4748732
Disease or Syndrome
MRT66 is a nonsyndromic autosomal recessive intellectual developmental disorder with delayed speech development, neuropsychiatric symptoms, and relatively normal life span (Philips et al., 2017).
Vertebral anomalies and variable endocrine and T-cell dysfunction
MedGen UID:
1648299
Concept ID:
C4748741
Disease or Syndrome
Vertebral anomalies and variable endocrine and T-cell dysfunction is a syndrome characterized by an overlapping spectrum of features. Skeletal malformations primarily involve the vertebrae, and endocrine abnormalities involving parathyroid hormone (PTH; 168450), growth hormone (GH1; 139250), and the thyroid gland have been reported. T-cell abnormalities have been observed, with some patients showing thymus gland aplasia or hypoplasia. Patients have mild craniofacial dysmorphism, and some show developmental delay or behavioral problems. Cardiac defects may be present (Liu et al., 2018).
Developmental and epileptic encephalopathy, 70
MedGen UID:
1648407
Concept ID:
C4749023
Disease or Syndrome
Developmental and epileptic encephalopathy-70 (DEE70) is neurologic disorder characterized by the onset of epileptic spasms or seizures in the first months of life. EEG may show hypsarrhythmia, consistent with a clinical diagnosis of West syndrome. Affected individuals show severely delayed psychomotor development with impaired or absent walking and language skills; intellectual impairment ranges from moderate to severe (summary by Hamada et al., 2018). For a discussion of genetic heterogeneity of DEE, see 308350.
Severe feeding difficulties-failure to thrive-microcephaly due to ASXL3 deficiency syndrome
MedGen UID:
1656239
Concept ID:
C4750837
Disease or Syndrome
ASXL3-related disorder is characterized by developmental delay or intellectual disability, typically in the moderate to severe range, with speech and language delay and/or absent speech. Affected individuals may also display autistic features. There may be issues with feeding. While dysmorphic facial features have been described, they are typically nonspecific. Affected individuals may also have hypotonia that can transition to spasticity resulting in unusual posture with flexion contractions of the elbows, wrists, and fingers. Other findings may include poor postnatal growth, strabismus, seizures, sleep disturbance, and dental anomalies.
Autosomal recessive spinocerebellar ataxia 20
MedGen UID:
1684324
Concept ID:
C5190595
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-20 is a neurodevelopmental disorder characterized by severely delayed psychomotor development with poor or absent speech, wide-based or absent gait, coarse facies, and cerebellar atrophy (summary by Thomas et al., 2014).
Menke-Hennekam syndrome 1
MedGen UID:
1675629
Concept ID:
C5193034
Disease or Syndrome
Menke-Hennekam syndrome-1 (MKHK1) is a congenital disorder characterized by variable impairment of intellectual development and facial dysmorphisms. Feeding difficulties, autistic behavior, recurrent upper airway infections, hearing impairment, short stature, and microcephaly are also frequently seen. Although mutations in the same gene cause Rubinstein-Taybi syndrome-1 (RSTS1; 180849), patients with MKHK1 do not resemble the striking phenotype of RSTS1. Genetic Heterogeneity of Menke-Hennekam Syndrome Menke-Hennekam syndrome-2 (MKHK2; 618333) is caused by heterozygous mutation in exons 30 or 31 of the EP300 gene (602700). Mutation elsewhere in that gene results in RSTS2 (613684).
Menke-Hennekam syndrome 2
MedGen UID:
1676668
Concept ID:
C5193035
Disease or Syndrome
Menke-Hennekam syndrome-2 (MKHK2) is a congenital disorder characterized by variable impairment of intellectual development and facial dysmorphisms. Feeding difficulties, autistic behavior, recurrent upper airway infections, and hearing impairment are also frequently seen. Although mutations in the same gene cause Rubinstein-Taybi syndrome-2 (RSTS2; 613684), patients with MKHK1 do not resemble the striking phenotype of RSTS2. For a discussion of genetic heterogeneity of Menke-Hennekam syndrome, see MKHK1 (618332).
Houge-Janssens syndrome 3
MedGen UID:
1677130
Concept ID:
C5193048
Disease or Syndrome
Houge-Janssens syndrome-3 (HJS3) is characterized by global developmental delay apparent from infancy. The phenotype is highly variable: patients may have hypotonia, behavioral abnormalities, and abnormalities on brain imaging, including enlarged ventricles, thin corpus callosum, and sometimes small brainstem. Many develop seizures, sometimes refractory, and some may have nonspecific dysmorphic features. Intellectual impairment can vary from mild to profound, and some patients may benefit from special education and respond well to speech therapy (summary by Reynhout et al., 2019). For a discussion of genetic heterogeneity of HJS, see HJS1 (616355).
Turnpenny-fry syndrome
MedGen UID:
1683283
Concept ID:
C5193060
Disease or Syndrome
Turnpenny-Fry syndrome (TPFS) is characterized by developmental delay, impaired intellectual development, impaired growth, and recognizable facial features that include frontal bossing, sparse hair, malar hypoplasia, small palpebral fissures and oral stoma, and dysplastic 'satyr' ears. Other common findings include feeding problems, constipation, and a range of brain, cardiac, vascular, and skeletal malformations (Turnpenny et al., 2018).
Intellectual developmental disorder, autosomal recessive 70
MedGen UID:
1679317
Concept ID:
C5193077
Disease or Syndrome
MRT70 is characterized primarily by impaired intellectual development. Mild facial dysmorphism, febrile seizures, and behavioral abnormalities have been reported in some patients (Maddirevula et al., 2018; Perez et al., 2018).
Developmental delay with variable intellectual impairment and behavioral abnormalities
MedGen UID:
1676192
Concept ID:
C5193092
Disease or Syndrome
Developmental delay with variable intellectual impairment and behavioral abnormalities (DDVIBA) is an autosomal dominant neurodevelopmental disorder. Most patients have impaired intellectual development with speech difficulties, and many have behavioral abnormalities, most commonly autism spectrum disorder (ASD), defects in attention, and/or hyperactivity. Many patients have dysmorphic features, although there is not a consistent gestalt. Additional more variable features may include hypotonia, somatic overgrowth with macrocephaly, mild distal skeletal anomalies, sleep disturbances, movement disorders, and gastrointestinal issues, such as constipation. The phenotype is highly variable (summary by Vetrini et al., 2019 and Torti et al., 2019).
Neurodevelopmental disorder with or without variable brain abnormalities; NEDBA
MedGen UID:
1675664
Concept ID:
C5193102
Disease or Syndrome
Neurodevelopmental disorder with or without variable brain abnormalities (NEDBA) is characterized by global developmental delay apparent from infancy or early childhood, resulting in mildly delayed walking, variably impaired intellectual development, and poor or absent speech. Additional features may include hypotonia, spasticity, or ataxia. About half of patients have abnormal findings on brain imaging, including cerebral or cerebellar atrophy, loss of white matter volume, thin corpus callosum, and perisylvian polymicrogyria. Seizures are not a prominent finding, and although some patients may have nonspecific dysmorphic facial features, there is no common or consistent gestalt (summary by Platzer et al., 2019).
Developmental delay with or without dysmorphic facies and autism
MedGen UID:
1679263
Concept ID:
C5193106
Disease or Syndrome
Developmental delay with or without dysmorphic facies and autism (DEDDFA) is a complex neurodevelopmental disorder apparent from infancy or early childhood and associated with variably impaired intellectual development. Some patients may be severely affected with no speech and inability to walk, whereas others may be able to attend special schools or have normal intellectual function associated with autism spectrum disorder and mild speech delay. Genetic analysis has suggested that the phenotype can be broadly categorized into 2 main groups. Patients with TRRAP mutations affecting residues 1031-1159 have a more severe disorder, often with multisystem involvement, including renal, cardiac, and genitourinary systems, as well as structural brain abnormalities. Patients with mutations outside of that region tend to have a less severe phenotype with a higher incidence of autism and usually no systemic involvement. Patients in both groups usually have somewhat similar dysmorphic facial features, such as upslanting palpebral fissures, hypertelorism, low-set ears, and broad or depressed nasal bridge, although these features are highly variable (summary by Cogne et al., 2019).
Intellectual developmental disorder with severe speech and ambulation defects
MedGen UID:
1682234
Concept ID:
C5193115
Disease or Syndrome
Intellectual developmental disorder with severe speech and ambulation defects (IDDSSAD) is an autosomal dominant neurodevelopmental disorder with onset of features in infancy or early childhood. Affected individuals have global developmental delay with impaired intellectual development and absent speech, and most cannot walk independently. Common dysmorphic features include prominent forehead and wide mouth (summary by Bell et al., 2019).
Generalized epilepsy with febrile seizures plus, type 10
MedGen UID:
1676426
Concept ID:
C5193120
Disease or Syndrome
Generalized epilepsy with febrile seizures plus-10 (GEFSP10) is a seizure disorder characterized by variable types of seizures, including absence, tonic-clonic, febrile, focal, and eyelid myoclonia. Onset tends to be in the first months or years of life, and the seizure type may evolve or even eventually remit. Some patients may have impaired intellectual development or autistic features. Brain imaging is usually normal (summary by Marini et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of GEFS+, see 604233.
Neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities
MedGen UID:
1682403
Concept ID:
C5193134
Disease or Syndrome
Stolerman neurodevelopmental syndrome (NEDSST) is a highly variable disorder characterized by developmental delay, often with motor and speech delay, mildly impaired intellectual development (in most patients), learning difficulties, and behavioral abnormalities, including autism spectrum disorder. Psychosis is observed in a small percentage of individuals over the age of 12 years. Most individuals have nonspecific and mild dysmorphic facial features without a common gestalt. A subset of patients may have involvement of other organ systems, including gastrointestinal with poor early feeding or gastroesophageal reflux, distal skeletal anomalies, and congenital heart defects. Most mutations occur de novo, but rare autosomal dominant inheritance with incomplete penetrance has been observed (Stolerman et al., 2019; Rots et al., 2023).
Shukla-Vernon syndrome
MedGen UID:
1674076
Concept ID:
C5193146
Disease or Syndrome
Shukla-Vernon syndrome (SHUVER) is an X-linked recessive neurodevelopmental disorder characterized by global developmental delay, variably impaired intellectual development, and behavioral abnormalities, including autism spectrum disorder and ADHD. Dysmorphic features are common and may include tall forehead, downslanting palpebral fissures, and tapering fingers. Some patients may have seizures and/or cerebellar atrophy on brain imaging. Carrier mothers may have mild manifestations, including learning disabilities (summary by Shukla et al., 2019).
Neutropenia, severe congenital, 8, autosomal dominant
MedGen UID:
1684816
Concept ID:
C5203411
Disease or Syndrome
Autosomal dominant severe congenital neutropenia-8 (SCN8) is a pleiotropic disorder with the consistent feature of decreased neutrophils associated with recurrent bacterial infections apparent from early infancy. Other hematologic parameters are usually normal, although some patients may have mild anemia. Bone marrow examination shows hypocellularity with arrested maturation of the granulocyte lineage at the level of promyelocytes or myeloblasts. Treatment with granulocyte colony-stimulating factor (GCSF; 138970) is usually ineffective or only partially effective, whereas hematopoietic bone marrow transplantation is effective. A subset of patients have additional features, including exocrine pancreatic insufficiency, which resembles Shwachman-Diamond syndrome (see SDS1, 260400), and/or neurologic deficits, including developmental delay, impaired intellectual development, speech delay, and/or autistic features (summary by Carapito et al., 2017 and Bellanne-Chantelot et al., 2018). For discussion of genetic heterogeneity of severe congenital neutropenia, see SCN1 (202700).
Intellectual developmental disorder 61
MedGen UID:
1684867
Concept ID:
C5231400
Disease or Syndrome
Autosomal dominant intellectual developmental disorder-61 (MRD61) is characterized by global developmental delay apparent in infancy with mildly impaired intellectual development, expressive speech delay, and behavioral abnormalities, including autism spectrum disorder and attention deficit-hyperactivity disorder (ADHD). Most affected individuals learn to walk on time or with some mild delay. Additional features are highly variable and may include nonspecific dysmorphic features, obstipation, ocular anomalies, and poor overall growth (Snijders Blok et al., 2018).
Developmental and epileptic encephalopathy, 78
MedGen UID:
1684724
Concept ID:
C5231409
Disease or Syndrome
Developmental and epileptic encephalopathy-78 (DEE78) is a severe neurologic disorder characterized by onset of refractory seizures in the first days or months of life followed by severely impaired intellectual development. Additional features may include cortical visual impairment, hypotonia, and abnormal movements, such as spasticity (summary by Butler et al., 2018). One family with an attenuated disease course has been reported (Maljevic et al., 2019). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Neurodevelopmental disorder with ataxia, hypotonia, and microcephaly
MedGen UID:
1684871
Concept ID:
C5231413
Disease or Syndrome
Neurodevelopmental disorder with cataracts, poor growth, and dysmorphic facies
MedGen UID:
1684661
Concept ID:
C5231414
Disease or Syndrome
Neurodevelopmental disorder with hypotonia and variable intellectual and behavioral abnormalities
MedGen UID:
1684818
Concept ID:
C5231423
Disease or Syndrome
Neurodevelopmental disorder with hypotonia and variable intellectual and behavioral abnormalities (NEDHIB) is characterized by early-onset hypotonia, delayed walking, poor speech, and impaired intellectual development. Additional features may include feeding difficulties, dysmorphic features, and visual defects. Brain imaging tends to show delayed myelination, thin corpus callosum, and/or enlarged ventricles. The severity of the disorder is highly variable; initial evidence suggests that the severity may depend on the type of mutation (summary by Haijes et al., 2019).
Snijders blok-fisher syndrome
MedGen UID:
1684801
Concept ID:
C5231424
Disease or Syndrome
Snijders Blok-Fisher syndrome (SNIBFIS) is a neurodevelopmental disorder characterized by global developmental delay, hypotonia, variable impaired intellectual development, and specifically impaired speech and language acquisition. Patients achieve independent ambulation and most have mildly to moderately impaired cognition with autistic features, although a few may develop seizures and have a more severe phenotype. Dysmorphic features include abnormal, cupped, or prominent ears and ocular anomalies. Mutations usually occur de novo, although 1 family with autosomal dominant inheritance has been reported (summary by Snijders Blok et al., 2019).
Weiss-kruszka syndrome
MedGen UID:
1684748
Concept ID:
C5231429
Disease or Syndrome
Weiss-Kruszka syndrome is characterized by metopic ridging or synostosis, ptosis, nonspecific dysmorphic features, developmental delay, and autistic features. Brain imaging may identify abnormalities of the corpus callosum. Developmental delay can present as global delay, motor delay, or speech delay. Affected individuals may also have ear anomalies, feeding difficulties (sometimes requiring placement of a gastrostomy tube), and congenital heart defects. There is significant variability in the clinical features, even between affected members of the same family.
Neurodevelopmental disorder with dysmorphic facies and distal skeletal anomalies
MedGen UID:
1684792
Concept ID:
C5231448
Disease or Syndrome
Neurodevelopmental disorder with dysmorphic facies and distal skeletal anomalies (NEDDFSA) is a global neurodevelopmental disorder with highly variable features. Patients often show poor feeding, poor overall growth, and hypotonia from early infancy, followed by mildly delayed motor development, poor language acquisition, and behavioral abnormalities. Intellectual development varies from severe with absent speech to mild with the ability to attend special schools. Common features include dysmorphic facial features with notable eye anomalies, joint hypermobility, and mild skeletal anomalies of the hands and feet (summary by Carapito et al., 2019).
Intellectual developmental disorder, autosomal recessive 72
MedGen UID:
1684805
Concept ID:
C5231452
Disease or Syndrome
Intellectual developmental disorder with speech delay, autism, and dysmorphic facies
MedGen UID:
1684848
Concept ID:
C5231456
Disease or Syndrome
Neurodevelopmental disorder with nonspecific brain abnormalities and with or without seizures
MedGen UID:
1684757
Concept ID:
C5231470
Disease or Syndrome
Neurodevelopmental disorder with nonspecific brain abnormalities is a highly variable syndrome characterized by impaired intellectual development and behavioral abnormalities associated with structural changes on brain imaging. Some patients have seizures, hypotonia, and scoliosis/kyphosis. Cognitive function ranges from severely impaired to the ability to attend schools with special assistance (summary by Fischer-Zirnsak et al., 2019).
Neurodevelopmental disorder with behavioral abnormalities, absent speech, and hypotonia
MedGen UID:
1684663
Concept ID:
C5231471
Disease or Syndrome
Neurodevelopmental disorder with behavioral abnormalities, absent speech, and hypotonia (NEDBASH) is an autosomal recessive disorder characterized by severely impaired intellectual and motor development, axial and peripheral hypotonia usually with inability to walk, and significant behavioral abnormalities consistent with autism spectrum disorder and reminiscent of Rett syndrome (RTT; 312750), such as poor communication, stereotypic or repetitive behaviors, hand-wringing, bruxism, and sleep disturbances. Other features include poor overall growth, and joint hypermobility. Rare features include seizures, dystonia, spasticity, and nonspecific brain abnormalities (summary by Abu-Libdeh et al., 2019 and Dias et al., 2019).
Intellectual developmental disorder with behavioral abnormalities and craniofacial dysmorphism with or without seizures
MedGen UID:
1684850
Concept ID:
C5231476
Disease or Syndrome
Patients with intellectual developmental disorder with behavioral abnormalities and craniofacial dysmorphism with or without seizures (IDDBCS) have impaired intellectual development or developmental delay of varying severity with impaired motor skills and language delay. Macrocephaly, obesity, and overgrowth are frequently seen. Approximately half of patients experience seizures, and neurobehavioral disorders including autism are usually present (Hamanaka et al., 2019; Kim et al., 2019).
Structural brain anomalies with impaired intellectual development and craniosynostosis
MedGen UID:
1684861
Concept ID:
C5231485
Disease or Syndrome
Patients with BAIDCS have small head circumference with abnormalities in brain anatomy including variable deficiency of the corpus callosum (including agenesis), abnormal conformation of the ventricles and posterior fossa, hypoplasia of both cerebellar hemispheres, colpocephaly, and partial rhombencephalosynapsis (absence of the cerebellar vermis with fusion of the cerebellar hemispheres). Intellectual development is moderately to severely impaired. Bicoronal synostosis, scoliosis, and tethered cord may be present (Twigg et al., 2015; Vandervore et al., 2018). Craniosynostosis-6 (CRS6; 616602) is an allelic disorder.
Intellectual developmental disorder with hypotonia and behavioral abnormalities
MedGen UID:
1684709
Concept ID:
C5231489
Disease or Syndrome
Intellectual developmental disorder with hypotonia and behavioral abnormalities (IDDHBA) is a neurodevelopmental disorder characterized by onset of hypotonia and variably impaired global developmental delay in infancy. Affected individuals tend to have learning disability, usually requiring special schooling, as well as behavioral abnormalities, such as autistic features and attention deficit-hyperactivity disorder (ADHD). Additional more variable features may include nonspecific dysmorphic facial features, congenital heart defects, visual or ocular movement anomalies, and poor feeding and/or gastroesophageal reflux (summary by Calpena et al., 2019).
Neurodevelopmental disorder with hypotonia and autistic features with or without hyperkinetic movements
MedGen UID:
1684874
Concept ID:
C5231491
Disease or Syndrome
Neurodevelopmental disorder with hypotonia and autistic features with or without hyperkinetic movements (NEDHAHM) is characterized by axial hypotonia apparent from birth, global developmental delay with impaired intellectual development and poor or absent language acquisition, and behavioral abnormalities, including autistic features, poor social interaction, and hang-wringing. Most patients have childhood-onset seizures that are usually responsive to medication, and a subset of patients develop cortical visual impairment and involuntary hyperkinetic movements, including chorea and dystonia. Some of the features are reminiscent of Rett syndrome (RTT; 312750) (summary by Salpietro et al., 2019).
Intellectual developmental disorder 60 with seizures
MedGen UID:
1684702
Concept ID:
C5231497
Disease or Syndrome
Autosomal dominant intellectual developmental disorder-60 with seizures is characterized by global developmental delay apparent in infancy, followed by onset of seizures in the first years of life. Patients have delayed walking, an ataxic gait, and moderately to severely impaired intellectual development with poor speech (summary by Helbig et al., 2019).
Developmental and epileptic encephalopathy, 85, with or without midline brain defects
MedGen UID:
1708832
Concept ID:
C5393312
Disease or Syndrome
Developmental and epileptic encephalopathy-85 with or without midline brain defects (DEE85) is an X-linked neurologic disorder characterized by onset of severe refractory seizures in the first year of life, global developmental delay with impaired intellectual development and poor or absent speech, and dysmorphic facial features. The seizures tend to show a cyclic pattern with clustering. Many patients have midline brain defects on brain imaging, including thin corpus callosum and/or variable forms of holoprosencephaly (HPE). The severity and clinical manifestations are variable. Almost all reported patients are females with de novo mutations predicted to result in a loss of function (LOF). However, some patients may show skewed X inactivation, and the pathogenic mechanism may be due to a dominant-negative effect. The SMC1A protein is part of the multiprotein cohesin complex involved in chromatid cohesion during DNA replication and transcriptional regulation; DEE85 can thus be classified as a 'cohesinopathy' (summary by Symonds et al., 2017 and Kruszka et al., 2019). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Intellectual developmental disorder 62
MedGen UID:
1712636
Concept ID:
C5394083
Disease or Syndrome
DLG4-related synaptopathy is a condition that affects neurological development. This condition is characterized by delayed development and mild to moderate intellectual disabilities that typically becomes evident before age 2. Over time, many individuals with DLG4-related synaptopathy lose skills that they have learned, such as speech or motor skills. About 20 percent of people with this condition cannot speak. Affected individuals often have neurodevelopmental disorders, such as autism spectrum disorder or attention-deficit/hyperactivity disorder. About half of individuals with this condition have recurrent seizures (epilepsy) that typically begin in childhood. Brain changes can also occur. These include brain tissue loss (atrophy) and abnormalities of the tissue connecting the left and right halves of the brain (corpus callosum) or the  hippocampus, which is a region of the brain that is involved in learning and memory.\n\nIndividuals with DLG4-related synaptopathy can also have weak muscle tone (hyptonia), loose joints (joint laxity), or a spine that curves to the side (scoliosis). Movement problems, including impaired muscle coordination (ataxia), involuntary muscle coordination (dystonia), or rhythmic shaking (tremor) are common in people with this condition. Other problems can include migraine, sleep problems, or anxiety. Some people with DLG4-related synaptopathy have a distinctive body type that includes a long face, slim body, and long fingers.\n\nLess commonly, DLG4-related synaptopathy can affect a person's vision. Affected individuals can have eyes that do not point in the same direction (strabismus), farsightedness (hyperopia), or involuntary movements of the eyes (nystagmus). Some affected individuals have blindness because the area of the brain responsible for processing vision is impaired. \n\nDLG4-related synaptopathy can also cause gastrointestinal difficulties that make it difficult to eat. These can include a backflow of stomach acids into the esophagus (gastroesophageal reflux disease or GERD).\n\n
Beck-Fahrner syndrome
MedGen UID:
1711894
Concept ID:
C5394097
Disease or Syndrome
Beck-Fahrner syndrome (BEFAHRS) is a developmental disorder characterized by global developmental delay with variably impaired intellectual development. Affected individuals often have behavioral abnormalities, such as autistic features or attention deficit-hyperactivity disorder (ADHD), as well as learning disabilities. Most patients have hypotonia and dysmorphic facies. Some may have growth abnormalities, including overgrowth or poor growth, poor feeding, and rarely, seizures. Although both monoallelic and biallelic mutations have been reported, some heterozygous carriers in autosomal recessive families may have milder symptoms; thus, both groups are included in this entry (summary by Beck et al., 2020).
Basal ganglia calcification, idiopathic, 8, autosomal recessive
MedGen UID:
1713414
Concept ID:
C5394199
Disease or Syndrome
Autosomal recessive idiopathic basal ganglia calcification-8 (IBGC8) is a progressive neurologic disorder with insidious onset of motor symptoms in adulthood. Affected individuals develop gait difficulties, parkinsonism, pyramidal signs, and dysarthria. Some may demonstrate cognitive decline or memory impairment. Brain imaging shows extensive calcifications in various brain regions including the basal ganglia, thalamus, and cerebellum. Because serum calcium and phosphate are normal, the disorder is thought to result from defects in the integrity of the neurovascular unit in the brain (summary by Schottlaender et al., 2020). For a phenotypic description and a discussion of genetic heterogeneity of IBGC, see IBGC1 (213600).
Autism, susceptibility to, 20
MedGen UID:
1717195
Concept ID:
C5394226
Finding
Alopecia-intellectual disability syndrome 4
MedGen UID:
1713432
Concept ID:
C5394241
Disease or Syndrome
Alopecia-intellectual disability syndrome-4 (APMR4) is characterized by alopecia universalis, scaly skin, and psychomotor retardation of varying degrees (Besnard et al., 2019). For a discussion of genetic heterogeneity of alopecia-intellectual disability syndrome, see APMR1 (203650).
Diets-Jongmans syndrome
MedGen UID:
1714920
Concept ID:
C5394263
Disease or Syndrome
Diets-Jongmans syndrome (DIJOS) is an autosomal dominant disorder characterized by mild to moderately impaired intellectual development with a recognizable facial gestalt (summary by Diets et al., 2019).
Neurodevelopmental disorder with or without autistic features and/or structural brain abnormalities
MedGen UID:
1714862
Concept ID:
C5394311
Disease or Syndrome
Neurodevelopmental disorder with or without autistic features and/or structural brain abnormalities (NEDASB) is an early-onset neurologic disorder characterized by global developmental delay, poor or absent speech and language development, and behavioral abnormalities reminiscent of autism spectrum disorder (ASD; 209850) or Angelman syndrome (AS; 105830). Additional features may include poor overall growth with small head circumference, axial hypotonia, spasticity, and seizures. Some patients have abnormal findings on brain imaging, including cerebral atrophy, cerebellar atrophy, and/or thin corpus callosum (summary by Mattioli et al., 2020).
Nizon-Isidor syndrome
MedGen UID:
1715748
Concept ID:
C5394350
Disease or Syndrome
Nizon-Isidor syndrome (NIZIDS) is a neurodevelopmental disorder characterized by global developmental delay, mildly delayed walking, poor speech and language, variably impaired intellectual development, and behavioral abnormalities, such as autistic features or attention deficit-hyperactivity disorder (ADHD). Some patients may have additional features, including nonspecific facial dysmorphism, gastrointestinal difficulties, distal hand anomalies, and thin corpus callosum on brain imaging (summary by Nizon et al., 2019).
Lissencephaly 10
MedGen UID:
1719546
Concept ID:
C5394354
Disease or Syndrome
Lissencephaly-10 (LIS10) is a neurologic disorder characterized by variably delayed development with mildly to moderately impaired intellectual development and language delay, as well as seizures, which are often intractable. There is a spectrum of severity, with some patients having normal early development and only borderline to mild cognitive impairment. Brain imaging shows features consistent with neuronal migration defects, including posterior-predominant lissencephaly, pachygyria, agyria, and subcortical band heterotopia (summary by Tsai et al., 2020). For a general description and a discussion of genetic heterogeneity of lissencephaly, see LIS1 (607432).
Congenital disorder of glycosylation, type iit
MedGen UID:
1709627
Concept ID:
C5394387
Disease or Syndrome
Congenital disorder of glycosylation type IIt (CDG2t) is an autosomal recessive multisystemic metabolic disorder characterized by global developmental delay, poor overall growth, severely impaired intellectual development with absent language, and behavioral abnormalities. Most patients develop early-onset seizures; brain imaging tends to show white matter abnormalities. Variable dysmorphic features, including long face, almond-shaped eyes, protruding maxilla, and short philtrum, are also present. The disorder, which is associated with low levels of HDL cholesterol, results from defective posttranslational O-linked glycosylation of certain plasma lipids and proteins (summary by Zilmer et al., 2020). For an overview of congenital disorders of glycosylation, see CDG1A (212065) and CDG2A (212066).
Intellectual developmental disorder with autistic features and language delay, with or without seizures
MedGen UID:
1715081
Concept ID:
C5394447
Disease or Syndrome
Intellectual developmental disorder with autistic features and language delay, with or without seizures (IDDALDS), is a neurodevelopmental disorder characterized by global developmental delay, variable intellectual disability, impaired speech development, and behavioral abnormalities, most commonly on the autism spectrum. About half of patients develop seizures; brain imaging is typically normal. Additional features are highly variable, but may include chronic constipation, walking difficulties, and dysmorphic facial features (summary by Guo et al., 2019).
Neurodevelopmental, jaw, eye, and digital syndrome
MedGen UID:
1712714
Concept ID:
C5394477
Disease or Syndrome
Neurodevelopmental, jaw, eye, and digital syndrome (NEDJED) is characterized by phenotypic diversity, with patients exhibiting a range of overlapping phenotypes. Most patients show developmental delay ranging from mild to severe, and often have behavioral disorders as well. Brain imaging shows hypoplasia of the corpus callosum, prominence of lateral ventricles, and/or white matter abnormalities. Many patients have retro- or micrognathia, but mild prognathism has also been observed. Ocular anomalies are variably present, and may be severe and complex; however, some patients show only mild myopia. Abnormalities of fingers and toes include brachydactyly, clinodactyly, syndactyly, and contractures; polydactyly is rarely seen (Holt et al., 2019).
Neurodevelopmental disorder with language impairment and behavioral abnormalities
MedGen UID:
1708389
Concept ID:
C5394502
Disease or Syndrome
Neurodevelopmental disorder with speech impairment and behavioral abnormalities (NEDLIB) is characterized by impaired intellectual development or developmental delay, behavioral abnormalities including autistic features, and language impairment. Other features include seizures and developmental regression (Salpietro et al., 2019).
Periventricular nodular heterotopia 9
MedGen UID:
1718470
Concept ID:
C5394503
Disease or Syndrome
Periventricular nodular heterotopia-9 (PVNH9) is an autosomal dominant neurologic disorder characterized as a malformation of cortical development. Anterior predominant PVNH, thin corpus callosum, and decreased white matter volume are found on brain imaging, but the clinical effects are variable. Most patients have impaired intellectual development and cognitive defects associated with low IQ (range 50 to 80), learning disabilities, and behavior abnormalities. Some patients develop seizures that tend to have a focal origin. However, some mutation carriers may be less severely affected with borderline or even normal IQ, suggesting incomplete penetrance of the phenotype (summary by Heinzen et al., 2018, Walters et al., 2018). For a discussion of genetic heterogeneity of periventricular nodular heterotopia, see 300049.
Agenesis of corpus callosum, cardiac, ocular, and genital syndrome
MedGen UID:
1718475
Concept ID:
C5394523
Disease or Syndrome
Agenesis of corpus callosum, cardiac, ocular, and genital syndrome (ACOGS) is a syndromic neurodevelopmental disorder characterized by global developmental delay and/or intellectual disability, corpus callosum agenesis or hypoplasia, craniofacial dysmorphisms, and ocular, cardiac, and genital anomalies (Accogli et al., 2019).
Cone-rod synaptic disorder syndrome, congenital nonprogressive
MedGen UID:
1773574
Concept ID:
C5436505
Disease or Syndrome
Congenital nonprogressive cone-rod synaptic disorder syndrome (CRSDS) is characterized by retinal and neurodevelopmental disease as well as occasional anomalies of glucose homeostasis. Patients exhibit low vision, photophobia, and nystagmus, and show an electronegative waveform in response to bright flash under dark adaptation on electroretinography, with severely reduced and delayed light-adapted responses. Neurodevelopmental features include poor to no language and autistic behaviors (Mechaussier et al., 2020).
Tolchin-Le Caignec syndrome
MedGen UID:
1724999
Concept ID:
C5436509
Disease or Syndrome
Tolchin-Le Caignec syndrome (TOLCAS) is a developmental disorder characterized by mildly to moderately impaired intellectual development and behavioral problems, such as autism, ADHD, labile mood, and aggressive episodes. Many patients have bony abnormalities, including osteochondroma, craniosynostosis, dysmorphic facies, arachnodactyly, and large head circumference. Rarely, additional congenital anomalies may also be observed. These additional features and the bony defects are highly variable (summary by Tolchin et al., 2020).
Li-Ghorbani-Weisz-Hubshman syndrome
MedGen UID:
1763263
Concept ID:
C5436525
Disease or Syndrome
Li-Ghorbani-Weisz-Hubshman syndrome (LIGOWS) is a neurodevelopmental disorder characterized by global developmental delay, mild to moderately impaired intellectual development with language delay, and mild dysmorphic features. Affected individuals may have behavioral abnormalities and difficulties with numbers and understanding certain concepts, such as money. Some patients have seizures. Brain imaging often shows enlarged ventricles, thin corpus callosum, and gray matter nodular heterotopia, suggesting abnormal cortical brain development. More variable additional features may be present (summary by Li et al., 2020).
Intellectual developmental disorder with seizures and language delay
MedGen UID:
1740295
Concept ID:
C5436574
Disease or Syndrome
SETD1B-related neurodevelopmental disorder (SETD1B-NDD) is characterized by developmental delay (mainly affecting speech and language), intellectual disability, seizures, autism spectrum disorder or autism-like behaviors, and additional behavioral concerns. Speech delay and/or language disorder has been reported in most affected individuals. Delay in gross motor skills and mild-to-moderate intellectual disability are common. Most affected individuals have seizures with variable onset and seizure type. Behavioral issues including hyperactivity, aggression, anxiety, and sleep disorders have been reported in approximately half of individuals. Less common features include ophthalmologic manifestations and feeding issues.
Neurodevelopmental disorder with dysmorphic facies, impaired speech, and hypotonia
MedGen UID:
1776912
Concept ID:
C5436585
Disease or Syndrome
Neurodevelopmental disorder with dysmorphic facies, impaired speech, and hypotonia (NEDDISH) is an autosomal recessive disorder characterized by global developmental delay and mildly to severely impaired intellectual development with poor speech and language acquisition. Some patients may have early normal development with onset of the disorder in the first years of life. More variable neurologic abnormalities include hypotonia, seizures, apnea, mild signs of autonomic or peripheral neuropathy, and autism. Aside from dysmorphic facial features and occasional findings such as scoliosis or undescended testes, other organ systems are not involved (summary by Schneeberger et al., 2020).
Neurodevelopmental disorder with speech impairment and dysmorphic facies
MedGen UID:
1758434
Concept ID:
C5436699
Disease or Syndrome
Neurodevelopmental disorder with speech impairment and dysmorphic facies (NEDSID) is characterized by developmental delay associated with mild to moderately impaired intellectual development or learning difficulties, behavioral or psychiatric abnormalities, and delayed speech and language acquisition. Additional features include dysmorphic facies, distal limb anomalies, gastrointestinal problems or feeding difficulties, and hypotonia. The phenotypic features and severity of the disorder are variable (summary by Kummeling et al., 2021).
Delpire-McNeill syndrome
MedGen UID:
1725056
Concept ID:
C5436771
Disease or Syndrome
Delpire-McNeill syndrome (DELMNES) is a neurodevelopmental disorder with highly variable manifestations. Patients present in infancy with global developmental delay, including motor, speech, and impaired intellectual development. The most severely affected patients have hypotonia, inability to hold their head or walk, bilateral sensorineural deafness, and absent language, whereas others have delayed walking and mild to moderate intellectual disability, often with speech delay and autistic features. More variable features may include spasticity or minor involvement of other organ systems, such as hip dislocation or ventricular septal defect (summary by McNeill et al., 2020).
COACH syndrome 3
MedGen UID:
1755565
Concept ID:
C5436841
Disease or Syndrome
COACH syndrome is classically defined as Cerebellar vermis hypoplasia, Oligophrenia, Ataxia, Colobomas, and Hepatic fibrosis (Verloes and Lambotte, 1989). Brain MRI demonstrates the molar tooth sign, which is a feature of Joubert syndrome. The disorder has been described as a Joubert syndrome-related disorder with liver disease (summary by Doherty et al., 2010). For a general phenotypic description and a discussion of genetic heterogeneity of COACH syndrome, see 216360.
Lessel-Kreienkamp syndrome
MedGen UID:
1762595
Concept ID:
C5436892
Disease or Syndrome
Lessel-Kreienkamp syndrome (LESKRES) is a neurodevelopmental disorder characterized by global developmental delay with intellectual disability and speech and language delay apparent from infancy or early childhood. The severity of the disorder is highly variable: some patients have mildly delayed walking and mild cognitive deficits, whereas others are nonambulatory and nonverbal. Most have behavioral disorders. Additional features, including seizures, hypotonia, gait abnormalities, visual defects, cardiac defects, and nonspecific dysmorphic facial features, may also be present (summary by Lessel et al., 2020).
AMED syndrome, digenic
MedGen UID:
1754257
Concept ID:
C5436906
Disease or Syndrome
AMED syndrome (AMEDS) is an autosomal recessive digenic multisystem disorder characterized by global developmental delay with impaired intellectual development, onset of bone marrow failure and myelodysplastic syndrome (MDS) in childhood, and poor overall growth with short stature (summary by Oka et al., 2020). For a discussion of genetic heterogeneity of bone marrow failure syndrome (BMFS), see BMFS1 (614675).
Neurodevelopmental disorder with or without early-onset generalized epilepsy
MedGen UID:
1737097
Concept ID:
C5436914
Disease or Syndrome
Neurodevelopmental disorder with or without early-onset generalized epilepsy (NEDEGE) is characterized by global developmental delay apparent from infancy or early childhood. Affected individuals have variably impaired intellectual development, speech delay, and behavioral abnormalities. About half of patients develop early-onset generalized epilepsy with different seizure types; myoclonic seizures and myoclonic-atonic epilepsy are commonly observed. The seizures may remit with age or remain refractory to treatment. Brain imaging is essentially normal and there are no significant accompanying neurologic or systemic abnormalities (summary by Mulhern et al., 2018).
Blepharophimosis-impaired intellectual development syndrome
MedGen UID:
1779966
Concept ID:
C5443984
Disease or Syndrome
Blepharophimosis-impaired intellectual development syndrome (BIS) is a congenital disorder characterized by a distinct facial appearance with blepharophimosis and global development delay. Affected individuals have delayed motor skills, sometimes with inability to walk, and impaired intellectual development with poor or absent speech; some patients show behavioral abnormalities. There are recognizable facial features, including epicanthal folds, sparse eyebrows, broad nasal bridge, short nose with downturned tip, and open mouth with thin upper lip. Other more variable features include distal skeletal anomalies, feeding difficulties with poor growth, respiratory infections, and hypotonia with peripheral spasticity (summary by Cappuccio et al., 2020).
Coffin-Siris syndrome 12
MedGen UID:
1782096
Concept ID:
C5444111
Disease or Syndrome
Coffin-Siris syndrome-12 (CSS12) is a neurodevelopmental disorder characterized by global developmental delay with variably impaired intellectual development, speech and language delay, and behavioral abnormalities, such as autism or hyperactivity. Affected individuals may have hypotonia and poor feeding in infancy. There are variable dysmorphic facial features, although most patients do not have the classic hypoplastic fifth digit/nail abnormalities that are often observed in other forms of CSS (Barish et al., 2020). For a general phenotypic description and a discussion of genetic heterogeneity of Coffin-Siris syndrome, see CSS1 (135900).
Multiple congenital anomalies-neurodevelopmental syndrome, X-linked
MedGen UID:
1788942
Concept ID:
C5542341
Disease or Syndrome
X-linked multiple congenital anomalies-neurodevelopmental syndrome (MCAND) is an X-linked recessive congenital multisystemic disorder characterized by poor growth, global developmental delay with impaired intellectual development, and variable abnormalities of the cardiac, skeletal, and genitourinary systems. Most affected individuals also have hypotonia and dysmorphic craniofacial features. Brain imaging typically shows enlarged ventricles and thin corpus callosum; some have microcephaly, whereas others have hydrocephalus. The severity of the disorder is highly variable, ranging from death in early infancy to survival into the second or third decade. Pathogenetically, the disorder results from disrupted gene expression and signaling during embryogenesis, thus affecting multiple systems (summary by Tripolszki et al., 2021 and Beck et al., 2021). Beck et al. (2021) referred to the disorder as LINKED syndrome (LINKage-specific deubiquitylation deficiency-induced Embryonic Defects).
Developmental and epileptic encephalopathy, 90
MedGen UID:
1786502
Concept ID:
C5542345
Disease or Syndrome
Developmental and epileptic encephalopathy-90 (DEE90) is an X-linked neurologic disorder characterized by onset of refractory seizures in the first days or months of life. Although most patients have focal seizures associated with oromotor automatisms and apnea, various seizure types may occur, including epileptic spasms, generalized tonic-clonic, and absence. EEG shows multifocal discharges; hypsarrhythmia, intermittent burst suppression, and slow spike-wave background resembling Lennox-Gastaut syndrome may also be observed. Affected individuals have global developmental delay with variable severity, but it is usually profound or severe. Some are unable to walk or speak, whereas others may achieve some milestones and show autistic features (summary by Fry et al., 2021). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Joubert syndrome 37
MedGen UID:
1786742
Concept ID:
C5543064
Disease or Syndrome
Joubert syndrome-37 (JBTS37) is an autosomal recessive neurodevelopmental ciliopathy characterized classically by a distinctive hindbrain malformation affecting the midbrain and cerebellum, recognizable as the 'molar tooth sign' on brain imaging. Affected individuals have hypotonia, ataxia, and variably impaired intellectual development. Additional variable features, such as postaxial polydactyly, liver or kidney anomalies, retinal dystrophy, and coloboma, may also occur. In severe cases, affected fetuses with these malformations may be terminated (summary by Latour et al., 2020). For a phenotypic description and a discussion of genetic heterogeneity of Joubert syndrome, see JBTS1 (213300).
Intellectual developmental disorder, autosomal dominant 64
MedGen UID:
1784554
Concept ID:
C5543067
Disease or Syndrome
Autosomal dominant intellectual developmental disorder-64 (MRD64) is characterized by mildly to severely impaired intellectual development (ID) with speech delays. Most patients also have autism spectrum disorder (ASD). Additional features are highly variable but may include motor delay, attention deficit-hyperactivity disorder (ADHD), and nonspecific dysmorphic features (summary by Mirzaa et al., 2020).
Neurodevelopmental disorder with or without autism or seizures
MedGen UID:
1784023
Concept ID:
C5543225
Disease or Syndrome
CUL3-related neurodevelopmental disorder is a condition that affects neurological and physical development. Children with CUL3-related neurodevelopmental disorder may have intellectual disability or specific learning disorders. They may also experience delayed development of speech and motor skills, such as sitting and walking. Some individuals with this condition may have autism spectrum disorder, a developmental condition that affects communication and social skills. \n\nMovement abnormalities can also occur in people with CUL3-related neurodevelopmental disorder. Affected individuals may have weak muscle tone (hypotonia) in childhood. In adulthood, they may develop involuntary muscle tensing (dystonia), rhythmic shaking (tremor), or other uncontrolled movements (spasms). \n\nPeople with CUL3-related neurodevelopmental disorder can have distinctive facial features, including a long, triangular-shaped face; a large forehead; a large, rounded nose; small ears; deep-set eyes; or a pointed chin. Some affected individuals have a larger than normal head (macrocephaly). \n\nMany people with CUL3-related neurodevelopmental disorder have hand and foot abnormalities. Hand abnormalities can include small pinky (fifth) fingers that curve inward (clinodactyly), narrow thumbs, underdevelopment of the muscle at the base of the thumb (thenar hypoplasia), or a single crease across the palm of the hand. Foot abnormalities can include high arches of the feet (pes cavus); bunions; fusion of the skin between some toes (cutaneous syndactyly); or joint deformities (contractures) in the ankles, feet, or toes. A few individuals with CUL3-related neurodevelopmental disorder have an abnormally curved lower back (lordosis) or a spine that curves to the side (scoliosis). \n\nSome affected infants have a backflow of stomach acids into the esophagus (gastroesophageal reflux disease or GERD), which tends to go away after childhood. Rarely, recurrent seizures (epilepsy), congenital heart abnormalities, or genitourinary abnormalities occur in people with CUL3-related neurodevelopmental disorder. 
Global developmental delay with speech and behavioral abnormalities
MedGen UID:
1787991
Concept ID:
C5543226
Disease or Syndrome
Global developmental delay with speech and behavioral abnormalities (GDSBA) is characterized by developmental delay apparent from infancy or early childhood. Affected individuals have mildly delayed fine and motor skills with walking by 3 years of age, mildly impaired intellectual development, speech and language delay, and variable behavioral abnormalities, mostly autism and ADHD. Some patients may have additional nonspecific features, such as facial dysmorphism, myopia or strabismus, and skeletal defects, including joint hypermobility, pes planus, or slender fingers (summary by Granadillo et al., 2020).
Neurodevelopmental disorder with cerebral atrophy and variable facial dysmorphism
MedGen UID:
1786662
Concept ID:
C5543228
Disease or Syndrome
Neurodevelopmental disorder with cerebral atrophy and facial dysmorphism (NEDCAFD) is an autosomal recessive disorder characterized by global developmental delay apparent from birth. Affected individuals have hypotonia with inability to walk and severely impaired intellectual development with absent language. Most patients have variable dysmorphic facial features including prominent eyes, protruding and low-set ears, and thin upper lip. Brain imaging shows cerebral atrophy, corpus callosum hypoplasia, and a simplified gyral pattern (summary by Rasheed et al., 2021).
KINSSHIP syndrome
MedGen UID:
1779339
Concept ID:
C5543317
Disease or Syndrome
KINSSHIP syndrome (KINS) is an autosomal dominant disorder characterized by a recognizable pattern of anomalies including developmental delay, impaired intellectual development, seizures, mesomelic dysplasia, dysmorphic facial features, horseshoe or hypoplastic kidney, and failure to thrive (summary by Voisin et al., 2021).
Hiatt-Neu-Cooper neurodevelopmental syndrome
MedGen UID:
1785187
Concept ID:
C5543338
Disease or Syndrome
Hiatt-Neu-Cooper neurodevelopmental syndrome (HINCONS) is characterized by global developmental delay with delayed walking or inability to walk and impaired intellectual development with poor or absent speech. Affected individuals have axial hypotonia and dysmorphic facies. Additional more variable features may include seizures, autistic or behavioral abnormalities, and brain abnormalities, such as dysplastic corpus callosum or polymicrogyria (summary by Hiatt et al., 2018).
Radio-Tartaglia syndrome
MedGen UID:
1778557
Concept ID:
C5543339
Disease or Syndrome
Radio-Tartaglia syndrome (RATARS) is a neurodevelopmental disorder characterized by global developmental delay with impaired intellectual development, speech delay, and variable behavioral abnormalities. Affected individuals show hypotonia, mild motor difficulties, and craniofacial dysmorphism. Brain imaging may show nonspecific defects; rare patients have seizures or pyramidal signs. A subset of individuals may have congenital heart defects, precocious puberty, and obesity in females. Some of the features are similar to those observed in patients with chromosome 1p36 deletion syndrome (607872) (summary by Radio et al., 2021).
Oculogastrointestinal-neurodevelopmental syndrome
MedGen UID:
1779113
Concept ID:
C5543355
Disease or Syndrome
Oculogastrointestinal neurodevelopmental syndrome (OGIN) is characterized by microphthalmia and/or coloboma in association with other congenital anomalies, including imperforate anus, horseshoe kidney, and structural cardiac defects. Hearing loss and severe developmental delay are also observed in most patients (Zha et al., 2020; Mor-Shaked et al., 2021).
Intellectual developmental disorder, autosomal dominant 65
MedGen UID:
1787923
Concept ID:
C5543371
Disease or Syndrome
Autosomal dominant intellectual developmental disorder-65 (MRD65) is characterized by delayed motor and speech acquisition, variably impaired intellectual development, and behavioral abnormalities. Affected individuals also have dysmorphic facial features. Brain imaging may be normal or may show abnormalities, including cerebellar hypoplasia, poor development of the corpus callosum, dysmorphic hippocampus, and polymicrogyria. Feeding difficulties, hypotonia, and seizures may also be observed (Duncan et al., 2020).
Deafness, cataract, impaired intellectual development, and polyneuropathy
MedGen UID:
1781637
Concept ID:
C5543482
Disease or Syndrome
Deafness, cataract, impaired intellectual development, and polyneuropathy (DCIDP) is characterized by early-onset of deafness, cataract, severe developmental delay, and severely impaired intellectual development. Patients later develop polyneuropathy of the lower extremities, associated with depigmentation of the hair in that area (Kroll-Hermi et al., 2020).
Faundes-Banka syndrome
MedGen UID:
1782083
Concept ID:
C5543554
Disease or Syndrome
Faundes-Banka syndrome (FABAS) is an autosomal dominant disorder characterized by variable combinations of developmental delay and microcephaly, as well as micrognathia and other dysmorphic features (Faundes et al., 2021).
Spinocerebellar ataxia, autosomal recessive 31
MedGen UID:
1786855
Concept ID:
C5543627
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-31 (SCAR31) is a complex neurodevelopmental disorder characterized by global developmental delay with hypotonia and variably impaired intellectual and language development. Affected individuals have an ataxic gait, tremor, and dysarthria; more severely affected patients also have spasticity with inability to walk. Most have optic atrophy. Brain imaging shows cerebellar hypoplasia, enlarged ventricles, and atrophy of the posterior corpus callosum. Additional features may include retinitis pigmentosa, sensorineural deafness, dysmorphic facial features, and possibly endocrine dysfunction (summary by Collier et al., 2021).
Neurodevelopmental disorder with dysmorphic facies and thin corpus callosum
MedGen UID:
1790413
Concept ID:
C5551361
Disease or Syndrome
Neurodevelopmental disorder with dysmorphic facies and thin corpus callosum (NEDDFAC) is characterized by global developmental delay, impaired intellectual development with poor or absent speech and language, and dysmorphic facial features. Brain imaging tends to show thin corpus callosum and decreased white matter volume. Additional features such as seizures, cardiac defects, and behavioral abnormalities may also occur. The phenotype is variable (summary by Bina et al., 2020).
Neuroocular syndrome
MedGen UID:
1790414
Concept ID:
C5551362
Disease or Syndrome
Intellectual developmental disorder, X-linked, syndromic, with pigmentary mosaicism and coarse facies
MedGen UID:
1794140
Concept ID:
C5561930
Disease or Syndrome
X-linked syndromic intellectual developmental disorder with pigmentary mosaicism and coarse facies (MRXSPF) is characterized by a phenotypic triad of severe developmental delay, coarse facial dysmorphisms, and Blaschkoid pigmentary mosaicism. Additional clinical features may include epilepsy, orthopedic abnormalities, hypotonia, and growth abnormalities. The disorder affects both males and females (Villegas et al., 2019; Diaz et al., 2020).
Ritscher-Schinzel syndrome 4
MedGen UID:
1794149
Concept ID:
C5561939
Disease or Syndrome
Ritscher-Schinzel syndrome-4 (RTSC4) is characterized by a constellation of congenital anomalies, including dysmorphic craniofacial features and structural brain anomalies, such as Dandy-Walker malformation (220200), hindbrain malformations, or agenesis of the corpus callosum, associated with global developmental delay and impaired intellectual development. Congenital cardiac defects have been reported in 1 family (summary by Ritscher et al., 1987 and Jeanne et al., 2021). For a discussion of genetic heterogeneity of Ritscher-Schinzel syndrome, see RTSC1 (220210).
Usmani-Riazuddin syndrome, autosomal dominant
MedGen UID:
1794162
Concept ID:
C5561952
Disease or Syndrome
Autosomal dominant Usmani-Riazzudin syndrome (USRISD) is a neurodevelopmental disorder characterized by global developmental delay with impaired intellectual development and speech delay, hypotonia, and behavioral abnormalities, most commonly aggressive behavior. More variable additional features may include seizures and distal limb anomalies (summary by Usmani et al., 2021).
Neurodevelopmental disorder with motor and speech delay and behavioral abnormalities
MedGen UID:
1794164
Concept ID:
C5561954
Disease or Syndrome
Neurodevelopmental disorder with motor and speech delay and behavioral abnormalities (NEDMOSBA) is an autosomal recessive disorder characterized by global developmental delay apparent from early childhood. There is significant phenotypic variability: some patients achieve walking and talking after a few years, whereas others develop spastic tetraplegia with inability to walk independently and never gain proper speech. Affected individuals may have variable additional features, including poor overall growth, hypotonia, tremor, ocular anomalies, seizures, and nonspecific dysmorphic facial features (summary by Polla et al., 2021).
Developmental delay, impaired speech, and behavioral abnormalities
MedGen UID:
1794167
Concept ID:
C5561957
Disease or Syndrome
Developmental delay, impaired speech, and behavioral abnormalities (DDISBA) is characterized by global developmental delay apparent from early childhood. Intellectual disability can range from mild to severe. Additional variable features may include dysmorphic facial features, seizures, hypotonia, motor abnormalities such as Tourette syndrome or dystonia, and hearing loss (summary by Cousin et al., 2021).
Neurodevelopmental disorder with hypotonia and dysmorphic facies
MedGen UID:
1794184
Concept ID:
C5561974
Disease or Syndrome
Neurodevelopmental disorder with hypotonia and dysmorphic facies (NEDHYDF) is characterized by global developmental delay and hypotonia apparent from birth. Affected individuals have variably impaired intellectual development, often with speech delay and delayed walking. Seizures are generally not observed, although some patients may have single seizures or late-onset epilepsy. Most patients have prominent dysmorphic facial features. Additional features may include congenital cardiac defects (without arrhythmia), nonspecific renal anomalies, joint contractures or joint hyperextensibility, dry skin, and cryptorchidism. There is significant phenotypic variability in both the neurologic and extraneurologic manifestations (summary by Tan et al., 2022).
Chopra-Amiel-Gordon syndrome
MedGen UID:
1794185
Concept ID:
C5561975
Disease or Syndrome
Chopra-Amiel-Gordon syndrome (CAGS) is an autosomal dominant disorder characterized by developmental delay and/or impaired intellectual development, speech delay, facial dysmorphism, and variable other features, including recurrent bacterial infections, ophthalmologic abnormalities, and nonspecific brain abnormalities (Chopra et al., 2021).
Neurodevelopmental disorder with hypotonia and brain abnormalities
MedGen UID:
1794187
Concept ID:
C5561977
Disease or Syndrome
Neurodevelopmental disorder with hypotonia and brain abnormalities (NEDHYBA) is characterized by impaired development of motor skills, cognitive function, and speech acquisition beginning in infancy or early childhood. Some affected individuals may have feeding difficulties, seizures, behavioral abnormalities, and nonspecific dysmorphic facial features. Brain imaging shows variable abnormalities, including corpus callosum defects, cerebellar defects, and decreased white matter volume. There is significant phenotypic variability (summary by Duncan et al., 2021).
Neurodevelopmental disorder with seizures and brain abnormalities
MedGen UID:
1794189
Concept ID:
C5561979
Disease or Syndrome
Neurodevelopmental disorder with seizures and brain abnormalities (NEDSBA) is an autosomal recessive neurologic disorder characterized by global developmental delay and onset of seizures in the first months of life associated with structural brain defects on brain imaging. Additional features may include pigmentary retinopathy with poor visual fixation and spasticity (summary by Duncan et al., 2021).
Neurodevelopmental-craniofacial syndrome with variable renal and cardiac abnormalities
MedGen UID:
1794194
Concept ID:
C5561984
Disease or Syndrome
Neurodevelopmental-craniofacial syndrome with variable renal and cardiac abnormalities (NECRC) is an autosomal dominant disorder characterized by dysmorphic craniofacial features associated with mild developmental delay, mildly impaired intellectual development or learning difficulties, speech delay, and behavioral abnormalities. About half of patients have congenital anomalies of the kidney and urinary tract (CAKUT) and/or congenital cardiac defects, including septal defects (Connaughton et al., 2020).
Intellectual developmental disorder with hypotonia, impaired speech, and dysmorphic facies
MedGen UID:
1794207
Concept ID:
C5561997
Disease or Syndrome
Intellectual developmental disorder with hypotonia, impaired speech, and dysmorphic facies (IDDHISD) is characterized by global developmental delay with impaired intellectual development and poor or absent speech, hypotonia, ophthalmologic abnormalities, and nonspecific dysmorphic features. Some affected individuals have seizures, and a few have involvement of other organ systems (Goodman et al., 2021).
Developmental and epileptic encephalopathy 97
MedGen UID:
1794209
Concept ID:
C5561999
Disease or Syndrome
Developmental and epileptic encephalopathy-97 (DEE97) is characterized by developmental delay, epileptic encephalopathy, and impaired intellectual development. Other clinical features may include autistic features and hypotonia. For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Muscular dystrophy, limb-girdle, autosomal recessive 27
MedGen UID:
1794212
Concept ID:
C5562002
Disease or Syndrome
Autosomal recessive limb-girdle muscular dystrophy-27 (LGMDR27) is characterized by progressive muscle weakness primarily affecting the lower limbs and resulting in walking difficulty or loss of ambulation. The age at onset is highly variable, from infancy to young adulthood. Patients with infantile onset may have a more severe disease course with rapid progression. Upper limb involvement and distal muscle weakness may also occur. Additional more variable features include neck muscle weakness, scoliosis, and joint contractures. Less common features include impaired intellectual development or speech delay, cardiomyopathy, and cardiac arrhythmia. Muscle biopsy shows nonspecific dystrophic changes (Coppens et al., 2021). For a discussion of genetic heterogeneity of autosomal recessive limb-girdle muscular dystrophy, see LGMDR1 (253600).
Developmental delay with or without intellectual impairment or behavioral abnormalities
MedGen UID:
1794214
Concept ID:
C5562004
Disease or Syndrome
Developmental delay with or without intellectual impairment or behavioral abnormalities (DDIB) is an autosomal dominant disorder with a nonspecific phenotype of developmental delay. Additional features may include neonatal feeding problems, hypotonia, and dysmorphic facial features (Dulovic-Mahlow et al., 2019; van Woerden et al., 2021).
Neurodevelopmental disorder with impaired language and ataxia and with or without seizures
MedGen UID:
1794216
Concept ID:
C5562006
Disease or Syndrome
Neurodevelopmental disorder with impaired language and ataxia and with or without seizures (NEDLAS) is characterized by axial hypotonia and global developmental delay apparent in early infancy. Affected individuals have delayed walking with gait ataxia and poor language development. Behavioral abnormalities also commonly occur. The severity is highly variable: a subset of patients have a more severe phenotype with early-onset seizures resembling epileptic encephalopathy, inability to walk or speak, and hypomyelination on brain imaging (summary by Stolz et al., 2021).
Developmental delay, hypotonia, musculoskeletal defects, and behavioral abnormalities
MedGen UID:
1794222
Concept ID:
C5562012
Disease or Syndrome
Developmental delay, hypotonia, musculoskeletal defects, and behavioral abnormalities (DEHMBA) is an early-onset neurodevelopmental disorder characterized by these features. Affected individuals also have nonspecific and variable dysmorphic facial features that do not constitute a recognizable gestalt. Although the disorder is caused by truncating mutations in the SRCAP gene as is FLHS, the DEHMBA phenotype is clinically distinguishable from FLHS by the lack of short stature, brachydactyly, and delayed bone age, as well as absence of a specific facial appearance. There are some overlapping features between the 2 disorders, mainly impaired intellectual development and speech delay (summary by Rots et al., 2021).
Neurodevelopmental disorder with hypotonia and gross motor and speech delay
MedGen UID:
1794241
Concept ID:
C5562031
Disease or Syndrome
Neurodevelopmental disorder with hypotonia and gross motor and speech delay (NEDHMS) is an autosomal recessive disorder characterized by severe global developmental delay apparent from infancy. Affected individuals have axial hypotonia and limited ability to walk, including some who are nonambulatory with lower limb spasticity, impaired intellectual development, and poor or absent speech and language. Additional more variable features may include seizures, behavioral problems, distal skeletal anomalies, and dysmorphic facial features (Melo et al., 2021).
Marbach-Schaaf neurodevelopmental syndrome
MedGen UID:
1794260
Concept ID:
C5562050
Disease or Syndrome
Marbach-Schaaf neurodevelopmental syndrom (MASNS) is characterized by global developmental delay with speech delay and behavioral abnormalities, including autism spectrum disorder and ADHD. Affected individuals also show movement disorders, such as dyspraxia and apraxia. More variable features include high pain tolerance, sleep disturbances, and variable nonspecific dysmorphic features (summary by Marbach et al., 2021).
Rauch-Steindl syndrome
MedGen UID:
1794271
Concept ID:
C5562061
Disease or Syndrome
Rauch-Steindl syndrome (RAUST) is characterized by poor pre- and postnatal growth, sometimes with short stature and small head circumference, characteristic dysmorphic facial features, and variable developmental delay with delayed motor and speech acquisition and impaired intellectual function that can be mild. Other features may include hypotonia and behavioral abnormalities. The phenotype represents a mild form of Wolf-Hirschhorn syndrome (WHS; 194190), which is a contiguous gene deletion syndrome caused by heterozygous deletion of several genes on chromosome 4p16. The clinical features of RAUST are similar to but milder than those of WHS, with less severe dysmorphic facial features, less severe developmental disabilities in general, and absence of a seizure disorder. The phenotype and expressivity of RAUST is highly variable (summary by Rauch et al., 2001; Zanoni et al., 2021).
Immunodeficiency 91 and hyperinflammation
MedGen UID:
1794283
Concept ID:
C5562073
Disease or Syndrome
Immunodeficiency-91 and hyperinflammation (IMD91) is an autosomal recessive complex immunologic disorder characterized by both immunodeficiency and recurrent infections, often to viruses or mycobacteria, as well as by hyperinflammation with systemic involvement. Affected individuals present in infancy with variable features, including fever, infection, thrombocytopenia, renal or hepatic dysfunction, recurrent infections, or seizures. Most patients eventually develop hepatic or renal failure, compromised neurologic function, lymphadenopathy or hepatosplenomegaly, and multiorgan failure resulting in death. More variable features may include intermittent monocytosis, features of hemophagocytic lymphohistiocytosis (HLH), and serologic evidence of hyperinflammation. The disorder is thought to result from dysregulation of the interferon response to viral stimulation in the innate immune system (summary by Le Voyer et al., 2021; Vavassori et al., 2021).
Progressive spondyloepimetaphyseal dysplasia-short stature-short fourth metatarsals-intellectual disability syndrome
MedGen UID:
1800305
Concept ID:
C5568882
Disease or Syndrome
A rare genetic multiple congenital anomalies/dysmorphic syndrome with characteristics of global developmental delay and intellectual disability, progressive spondyloepimetaphyseal dysplasia, short stature, short fourth metatarsals and dysmorphic craniofacial features (including microcephaly, hypertelorism, epicanthal folds, mild ptosis, strabismus, malar hypoplasia, short nose, depressed nasal bridge, full lips, small, low-set ears and short neck). Craniosynostosis, generalized hypotonia, as well as asymmetry of the cerebral hemispheres and mild thinning of the corpus callosum on brain imaging have also been described.
Schaaf-Yang syndrome
MedGen UID:
1807366
Concept ID:
C5575066
Disease or Syndrome
Schaaf-Yang syndrome (SYS) is a rare neurodevelopmental disorder that shares multiple clinical features with the genetically related Prader-Willi syndrome. It usually manifests at birth with muscular hypotonia in all and distal joint contractures in a majority of affected individuals. Gastrointestinal/feeding problems are particularly pronounced in infancy and childhood, but can transition to hyperphagia and obesity in adulthood. Respiratory distress is present in many individuals at birth, with approximately half requiring intubation and mechanical ventilation, and approximately 20% requiring tracheostomy. Skeletal manifestations such as joint contractures, scoliosis, and decreased bone mineral density are frequently observed. All affected individuals show developmental delay, resulting in intellectual disability of variable degree, from low-normal intelligence to severe intellectual disability. Other findings may include short stature, seizures, eye anomalies, and hypogonadism.
Hypogonadotropic hypogonadism 26 with or without anosmia
MedGen UID:
1811919
Concept ID:
C5676903
Disease or Syndrome
HH26 is characterized by micropenis and cryptorchidism at birth in male patients, and absent puberty and anosmia in male or female patients. Some affected individuals also exhibit craniosynostosis (Davis et al., 2020). Congenital idiopathic hypogonadotropic hypogonadism (IHH) is a disorder characterized by absent or incomplete sexual maturation by the age of 18 years, in conjunction with low levels of circulating gonadotropins and testosterone and no other abnormalities of the hypothalamic-pituitary axis. Idiopathic hypogonadotropic hypogonadism can be caused by an isolated defect in gonadotropin-releasing hormone (GNRH; 152760) release, action, or both. Other associated nonreproductive phenotypes, such as anosmia, cleft palate, and sensorineural hearing loss, occur with variable frequency. In the presence of anosmia, idiopathic hypogonadotropic hypogonadism has been called 'Kallmann syndrome (KS),' whereas in the presence of a normal sense of smell, it has been termed 'normosmic idiopathic hypogonadotropic hypogonadism (nIHH)' (summary by Raivio et al., 2007). Because families have been found to segregate both KS and nIHH, the disorder is here referred to as 'hypogonadotropic hypogonadism with or without anosmia (HH).' For a discussion of genetic heterogeneity of hypogonadotropic hypogonadism with or without anosmia as well as a discussion of oligogenicity of this disorder, see 147950.
Bryant-Li-Bhoj neurodevelopmental syndrome 1
MedGen UID:
1801103
Concept ID:
C5676905
Disease or Syndrome
Bryant-Li-Bhoj neurodevelopmental syndrome-1 (BRYLIB1) is a highly variable phenotype characterized predominantly by moderate to severe global developmental delay with impaired intellectual development, poor or absent speech, and delayed motor milestones. Most patients have hypotonia, although some have peripheral hypertonia. Common features include abnormal head shape, variable dysmorphic facial features, oculomotor abnormalities, feeding problems, and nonspecific brain imaging abnormalities. Additional features may include hearing loss, seizures, short stature, and mild skeletal defects (summary by Bryant et al., 2020). Genetic Heterogeneity of Bryant-Li-Bhoj Neurodevelopmental Syndrome See also BRYLIB2 (619721), caused by heterozygous mutation in the H3F3B gene (601058).
Neurodevelopmental disorder with or without variable movement or behavioral abnormalities
MedGen UID:
1802087
Concept ID:
C5676908
Disease or Syndrome
Neurodevelopmental disorder with or without variable movement or behavioral abnormalities (NEDMAB) is an autosomal dominant disorder characterized by mildly to severely impaired intellectual development and, in some patients, movement abnormalities consisting of tremors, cerebellar ataxia, or extrapyramidal symptoms. Movement abnormalities have onset in childhood or adolescence. Other variable features include autism spectrum disorder or autistic features and epilepsy.
Teebi hypertelorism syndrome 2
MedGen UID:
1809276
Concept ID:
C5676911
Disease or Syndrome
Teebi hypertelorism syndrome-2 (TBHS2) is characterized primarily by hypertelorism, prominent forehead, thick and broad eyebrows, and short nose with depressed nasal root and broad nasal tip. Other features include thin upper lip, small chin with horizontal crease, and high or cleft palate. Developmental delay and/or impaired intellectual development have been observed in some patients (Li et al., 2021). For a general phenotypic description and a discussion of genetic heterogeneity of Teebi hypertelorism syndrome, see TBHS1 (145420).
Combined oxidative phosphorylation deficiency 54
MedGen UID:
1812715
Concept ID:
C5676912
Disease or Syndrome
Combined oxidative phosphorylation deficiency-54 (COXPD54) is an autosomal recessive disorder with pleiotropic multisystem presentations resulting from a disruption in mitochondrial transcription and translation. The phenotype is highly variable. Many patients have early-onset sensorineural hearing loss, sometimes in isolation, and sometimes associated with global developmental delay or primary ovarian failure. Other features may include peripheral hypertonia, seizures, muscle weakness, behavioral abnormalities, and leukoencephalopathy on brain imaging. Serum lactate may or may not be elevated (summary by Hochberg et al., 2021). For a discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (609060).
Tessadori-van Haaften neurodevelopmental syndrome 2
MedGen UID:
1803228
Concept ID:
C5676923
Disease or Syndrome
Tessadori-Bicknell-van Haaften neurodevelopmental syndrome-2 (TEBIVANED2) is characterized by poor overall growth, profound global developmental delay with absent speech, and characteristic dysmorphic facial features, including hypertelorism, abnormal nose, and wide mouth (Tessadori et al., 2020). For a discussion of genetic heterogeneity of Tessadori-Bicknell-van Haaften neurodevelopmental syndrome, see TEBIVANED1 (619758).
Kury-Isidor syndrome
MedGen UID:
1807460
Concept ID:
C5676925
Disease or Syndrome
Kury-Isidor syndrome (KURIS) is a neurodevelopmental disorder with a highly variable phenotype. It is characterized mainly by mild global developmental delay apparent from infancy or early childhood with walking delayed by a few years and speech delay, often with language deficits. Intellectual development may be mildly delayed, borderline, or even normal; most patients have behavioral problems, including autism. Additional variable systemic features may include poor overall growth, hypotonia, distal skeletal anomalies, seizures, and nonspecific dysmorphic facial features (summary by Kury et al., 2022).
Macrocephaly, neurodevelopmental delay, lymphoid hyperplasia, and persistent fetal hemoglobin
MedGen UID:
1802903
Concept ID:
C5676928
Disease or Syndrome
Macrocephaly, neurodevelopmental delay, lymphoid hyperplasia, and persistent fetal hemoglobin (MNDLFH) is characterized by clinically significant pharyngeal lymphoid hypertrophy, with adenoid overgrowth, frequent upper airway infections, and sleep apnea. Macrocephaly without structural brain abnormalities is present, and patients exhibit increased weight for height as well as delayed gross motor and impaired intellectual development; autistic features and attention-deficit hyperactivity disorder have also been reported. An increased fraction of fetal hemoglobin has been observed in some patients (Ohishi et al., 2020; von der Lippe et al., 2022).
Neurodevelopmental disorder with hypotonia, impaired speech, and behavioral abnormalities
MedGen UID:
1812577
Concept ID:
C5676975
Disease or Syndrome
Neurodevelopmental disorder with hypotonia, impaired speech, and behavioral abnormalities (NEDHISB) is characterized by global developmental delay apparent since infancy or early childhood, hypotonia with delayed motor development, impaired intellectual development with significant speech delay or absent speech, and variable behavioral abnormalities, such as autism, repetitive actions, or aggression. About two-thirds of patients have early-onset seizures that range from intractable to self-limiting. More variable features include nonspecific dysmorphic facial features, distal skeletal anomalies, and brain imaging abnormalities. The phenotypic manifestations and severity are highly variable (Muir et al., 2021).
Parenti-mignot neurodevelopmental syndrome
MedGen UID:
1808333
Concept ID:
C5676984
Disease or Syndrome
Parenti-Mignot neurodevelopmental syndrome (PMNDS) is an autosomal dominant neurodevelopmental disorder frequently characterized by impaired intellectual development, speech delay, motor delay, behavioral problems, and epilepsy (Parenti et al., 2021).
Neurodevelopmental disorder with language delay and seizures
MedGen UID:
1805816
Concept ID:
C5676998
Disease or Syndrome
Neurodevelopmental disorder with language delay and seizures (NEDLDS) is an autosomal recessive disorder characterized by global developmental delay with mild to severely impaired intellectual development and speech delay with poor or absent language. Affected individuals develop early-onset seizures that are usually well-controlled with medication. Additional features may include axial hypotonia, peripheral hypertonia, hypothyroidism, and nonspecific dysmorphic features or brain imaging abnormalities (Lu et al., 2022).
Intellectual developmental disorder, autosomal dominant 66
MedGen UID:
1812470
Concept ID:
C5677000
Mental or Behavioral Dysfunction
Autosomal dominant intellectual developmental disorder-66 (MRD66) is characterized by global developmental delay with mildly to moderately impaired intellectual development and mild speech delay. The phenotype and severity are highly variable. Some patients have behavioral problems or autism spectrum disorder, and about 50% have variable types of seizures. Additional features may include nonspecific dysmorphic facial features, tall or short stature, and mild skeletal anomalies (Rahimi et al., 2022).
Developmental and epileptic encephalopathy 103
MedGen UID:
1809962
Concept ID:
C5677002
Disease or Syndrome
Developmental and epileptic encephalopathy-103 (DEE103) is characterized by onset of various types of seizures in the first year of life, most of which are refractory to treatment. Affected individuals show global developmental delay with impaired intellectual development ranging from mild to severe. Additional features may include hypotonia, ataxia, and behavioral abnormalities, including autism and hyperactivity (Schwarz et al., 2022). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Intellectual developmental disorder, autosomal dominant 67
MedGen UID:
1805690
Concept ID:
C5677006
Mental or Behavioral Dysfunction
Autosomal dominant intellectual developmental disorder-67 (MRD67) is characterized by global developmental delay with variably impaired intellectual development apparent from infancy or early childhood. Additional features may include behavioral abnormalities, such as autism spectrum disorder (ASD) and ADHD, as well as language and sleeping difficulties. Brain imaging is normal (Ismail et al., 2022).
Dworschak-Punetha neurodevelopmental syndrome
MedGen UID:
1800957
Concept ID:
C5677017
Disease or Syndrome
Dworschak-Punetha neurodevelopmental syndrome (DWOPNED) is an autosomal recessive disorder characterized mainly by global developmental delay and mildly impaired intellectual development (IQ range 77 to 85), often with behavioral abnormalities, including autism spectrum disorder and hyperactivity. Some affected individuals may have only speech delay or behavioral manifestations. More variable additional features include optic disc hypoplasia, ptosis, hypo- or hyperpigmented skin lesions, nonspecific dysmorphic facial features, and brain imaging abnormalities of the ventricles or corpus callosum. Of note, not all patients exhibit all features, and there is significant inter- and intrafamilial phenotypic variability (Dworschak et al., 2021).
ACCES syndrome
MedGen UID:
1804308
Concept ID:
C5677019
Disease or Syndrome
Aplasia cutis congenita and ectrodactyly skeletal syndrome (ACCES) is characterized by highly variable expressivity, even within the same family. Most patients exhibit scalp defects, whereas ectrodactyly is less common; however, more variable and less obvious digital and skeletal anomalies are often present. Early growth deficiency and neurodevelopmental delay are also commonly seen (Schnur et al., 2021).
Chilton-Okur-Chung neurodevelopmental syndrome
MedGen UID:
1803276
Concept ID:
C5677022
Disease or Syndrome
Chilton-Okur-Chung neurodevelopmental syndrome (CHOCNS) is characterized mainly by global developmental delay with variably impaired intellectual development and occasional speech delay. Most patients have behavioral abnormalities, including autism spectrum disorder, ADHD, and aggression. About half of patients have dysmorphic facial features, and about half have nonspecific brain abnormalities, including thin corpus callosum. Rare involvement of other organ systems may be present. At least 1 child with normal development at age 2.5 years has been reported (Chilton et al., 2020).
Epilepsy, X-linked 1, with variable learning disabilities and behavior disorders
MedGen UID:
1823951
Concept ID:
C5774177
Disease or Syndrome
X-linked epilepsy-1 with variable learning disabilities and behavior disorders (EPILX1) is an X-linked neurologic disorder characterized by the onset of complex partial seizures in the first or second decades. The seizures are often triggered by showering or water-related hygiene activities, consistent with reflex bathing epilepsy. Additional spontaneous seizures and secondary generalization may also occur. Most patients have associated developmental defects, including learning disabilities, behavioral problems, or autistic features. The pathophysiology of the reflex seizures is thought to be hyperexcitability of the cortical or subcortical neuronal areas that respond to physiologic stimulus in an exaggerated manner, possibly due to aberrant synaptic maturation (summary by Nguyen et al., 2015; Sirsi et al., 2017; Accogli et al., 2021).
Neurodevelopmental disorder with gait disturbance, dysmorphic facies, and behavioral abnormalities, X-linked
MedGen UID:
1823953
Concept ID:
C5774179
Disease or Syndrome
Hijazi-Reis syndrome (HIJRS) is an X-linked dominant disorder characterized by global developmental delay with hypotonia, motor delay, impaired intellectual development, and speech and language delay. Affected individuals also have dysmorphic facial features, gastrointestinal issues, and ocular anomalies. Rare patients have seizures (Hijazi et al., 2022).
Developmental and epileptic encephalopathy 104
MedGen UID:
1823956
Concept ID:
C5774183
Disease or Syndrome
Developmental and epileptic encephalopathy-104 (DEE104) is an autosomal dominant disorder characterized by developmental delay in the first few months of life and drug-resistant focal and generalized tonic-clonic seizures (summary by Bott et al., 2021). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Intellectual developmental disorder with autism and dysmorphic facies
MedGen UID:
1823979
Concept ID:
C5774206
Disease or Syndrome
Intellectual developmental disorder with autism and dysmorphic facies (IDDADF) is an autosomal recessive neurodevelopmental disorder characterized by moderate to severely impaired cognitive development associated with behavioral abnormalities, including autism spectrum disorder. Affected individuals have variable dysmorphic facial features (Al-Amri et al., 2022)
Neurodevelopmental disorder with microcephaly, movement abnormalities, and seizures
MedGen UID:
1823981
Concept ID:
C5774208
Disease or Syndrome
Neurodevelopmental disorder with microcephaly, movement abnormalities, and seizures (NEDMIMS) is an autosomal recessive disorder characterized by severe global developmental delay apparent from infancy, impaired intellectual development, progressive microcephaly, and early-onset seizures that may be refractory to treatment. Affected individuals have poor overall growth and may have various movement abnormalities, including hypo- and hypertonia. Behavioral problems may also be observed (Klockner et al., 2022).
Developmental delay, behavioral abnormalities, and neuropsychiatric disorders
MedGen UID:
1823997
Concept ID:
C5774224
Disease or Syndrome
Developmental delay, behavioral abnormalities, and neuropsychiatric disorders (DEDBANP) is a neurodevelopmental disorder characterized by mild global developmental delay and normal or variably impaired intellectual development. Most individuals have behavioral or neuropsychiatric disorders, including autism spectrum disorder (ASD), attention deficit-hyperactivity disorder (ADHD), and executive functioning deficits. Additional features may include speech delay, dysmorphic features, hypotonia, sleep disturbances, and seizures (Vitobello et al., 2022).
Intellectual developmental disorder with ocular anomalies and distinctive facial features
MedGen UID:
1824011
Concept ID:
C5774238
Disease or Syndrome
Intellectual developmental disorder with ocular anomalies and distinctive facial features (IDDOF) is characterized by global developmental delay, mildly impaired intellectual development, ophthalmologic anomalies, microcephaly or relative microcephaly, hearing loss, and characteristic facial features (Huang et al., 2022).
Developmental delay with variable intellectual disability and dysmorphic facies
MedGen UID:
1824015
Concept ID:
C5774242
Disease or Syndrome
Developmental delay with variable intellectual disability and dysmorphic facies (DIDDF) is a clinically heterogeneous disorder characterized by neurologic deficits and characteristic dysmorphic facial features apparent from infancy or early childhood. Affected individuals usually show impaired intellectual development, speech delay, learning difficulties, and/or behavioral problems. Additional features may include hypotonia, hand or foot deformities, and palatal defects (Verberne et al., 2021; Verberne et al., 2022).
Neurodevelopmental disorder with growth retardation, dysmorphic facies, and corpus callosum abnormalities
MedGen UID:
1824024
Concept ID:
C5774251
Disease or Syndrome
Neurodevelopmental disorder with growth retardation, dysmorphic facies, and corpus callosum abnormalities (NEDGFC) is an autosomal recessive disorder characterized by these cardinal features apparent from infancy. There is phenotypic variability both in disease manifestations and severity. More severely affected individuals are unable to walk independently, are nonverbal, and may have other anomalies, including congenital heart defects, feeding difficulties, or skeletal defects, whereas others show mildly delayed motor and speech acquisition with mild or borderline intellectual disability (summary by von Elsner et al., 2022).
Developmental and epileptic encephalopathy 109
MedGen UID:
1824036
Concept ID:
C5774263
Disease or Syndrome
Developmental and epileptic encephalopathy-109 (DEE109) is characterized by the onset of various types of seizures in the first months or years of life. Affected individuals show developmental delay before and concurrent with the onset of seizures. Features include impaired intellectual development with poor speech, ataxic gait, coordination problems, and behavioral abnormalities (Manivannan et al., 2022). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Atelis syndrome 1
MedGen UID:
1824054
Concept ID:
C5774281
Disease or Syndrome
Atelis syndrome-1 (ATELS1) is an autosomal recessive neurodevelopmental disorder characterized by global developmental delay with learning difficulties and poor overall growth with short stature and microcephaly. Most patients have anemia, some have immunologic defects, and some have congenital heart septal defects. More variable features may include hypotonia, dysmorphic facial features, skin pigmentary anomalies, and mild skeletal defects. Patient cells show multiple chromosomal abnormalities due to impaired DNA replication and disrupted mitosis (Grange et al., 2022). See also ATELS2 (620185), caused by mutation in the SMC5 gene (609386) on chromosome 9q21. For a discussion of genetic heterogeneity of MVA, see MVA1 (257300).
Intellectual developmental disorder, X-linked 111
MedGen UID:
1840204
Concept ID:
C5829568
Mental or Behavioral Dysfunction
X-linked intellectual developmental disorder-111 (XLID111) is a neurodevelopmental disorder characterized by different degrees of impaired intellectual development associated with motor, speech, and behavioral impairments (El Chehadeh et al., 2022).
Intellectual developmental disorder, X-linked 112
MedGen UID:
1840225
Concept ID:
C5829589
Disease or Syndrome
X-linked intellectual disorder-112 (XLID112) is a neurodevelopmental disorder characterized by developmental delay, with speech delay more prominent than motor delay, autism or autism traits, and variable dysmorphic features. Affected females have been reported, which appears to be related to skewed X-inactivation (summary by Hiatt et al., 2023).
Neurodevelopmental disorder with hypotonia, dysmorphic facies, and skeletal anomalies, with or without seizures
MedGen UID:
1840880
Concept ID:
C5830244
Disease or Syndrome
Neurodevelopmental disorder with hypotonia, dysmorphic facies, and skeletal anomalies, with or without seizures (NEDFSS), is characterized by these features and global developmental delay with delayed or absent walking, moderate to severely impaired intellectual development, and poor or absent speech acquisition. Affected individuals may also have behavioral abnormalities. About half of patients develop various types of seizures that are usually well-controlled with medication. Rare patients are noted to have heat intolerance or insensitivity to pain (Lines et al., 2022).
Neurodevelopmental disorder with poor growth and behavioral abnormalities
MedGen UID:
1840909
Concept ID:
C5830273
Disease or Syndrome
Neurodevelopmental disorder with poor growth and behavioral abnormalities (NEDGBA) is an autosomal recessive disorder characterized by global developmental delay, moderately to severely impaired intellectual development, often with absent speech, and behavioral abnormalities, including hyperactivity, short attention span, and ADHD. Affected individuals show failure to thrive with poor overall growth; some have microcephaly. Additional features may include nonspecific facial dysmorphism, hypotonia, and feeding difficulties (Vogt et al., 2022; Meng et al., 2023).
Neurodevelopmental disorder with absent speech and movement and behavioral abnormalities
MedGen UID:
1840955
Concept ID:
C5830319
Mental or Behavioral Dysfunction
Neurodevelopmental disorder with absent speech and movement and behavioral abnormalities (NEDSMB) is an autosomal recessive disorder characterized by global developmental delay and severely impaired intellectual development with aggressive behavior. Mild dysmorphic features and hypodontia are also present (Faqeih et al., 2023).
Neurodevelopmental disorder with language delay and behavioral abnormalities, with or without seizures
MedGen UID:
1841001
Concept ID:
C5830365
Disease or Syndrome
Neurodevelopmental disorder with language delay and behavioral abnormalities, with or without seizures (NEDLBAS), is characterized by global developmental delay with variably impaired intellectual development apparent from infancy or early childhood. Affected individuals have significant speech delay, and most demonstrate behavioral abnormalities, including autistic features. About half of patients develop seizures, which may be controlled or refractory. More variable features include hypotonia, feeding difficulties, and subtle facial dysmorphism (Schalk et al., 2022).
Neurodevelopmental disorder with microcephaly and speech delay, with or without brain abnormalities
MedGen UID:
1841049
Concept ID:
C5830413
Disease or Syndrome
Neurodevelopmental disorder with microcephaly and speech delay, with or without brain abnormalities (NEDMSBA) is an autosomal recessive disorder characterized by global developmental delay, hypotonia, delayed or absent walking, impaired intellectual development, and poor or absent speech, apparent from early infancy. Affected individuals have postnatal progressive microcephaly and may show poor overall growth and dysmorphic facial features. Additional more variable features include cortical visual impairment, seizures, hypotonia, spasticity, and sensorineural deafness. Brain imaging is abnormal in most patients, showing myelination defects, cortical atrophy, or thin corpus callosum. There is phenotypic variability, even within families (Bogershausen et al., 2022; Lin et al., 2022).
Intellectual developmental disorder, autosomal dominant 71, with behavioral abnormalities
MedGen UID:
1841073
Concept ID:
C5830437
Mental or Behavioral Dysfunction
Autosomal dominant intellectual developmental disorder-71 with behavioral abnormalities (MRD71) is a neurodevelopmental disorder characterized by global developmental delay with hypotonia, speech delay, and variably impaired cognitive development. Almost all affected individuals show marked behavioral manifestations, including autism spectrum disorder (ASD), ADHD, hypersensitivity, and aggression. Many have dysmorphic features, although there is not a common gestalt (Harris et al., 2021).
Hatipoglu immunodeficiency syndrome
MedGen UID:
1841075
Concept ID:
C5830439
Disease or Syndrome
Hatipoglu immunodeficiency syndrome (HATIS) is an autosomal recessive immunologic disorder characterized by childhood onset of failure to thrive, skin manifestations, pancytopenia, and susceptibility to recurrent infections (Harapas et al., 2022).
Multiple mitochondrial dysfunctions syndrome 7
MedGen UID:
1841222
Concept ID:
C5830586
Disease or Syndrome
Mitochondrial dysfunctions syndrome-7 (MMDS7) is an autosomal recessive disorder characterized by a clinical spectrum ranging from neonatal fatal glycine encephalopathy to an attenuated phenotype of developmental delay, behavioral problems, limited epilepsy, and variable movement problems (Arribas-Carreira et al., 2023). For a general description and a discussion of genetic heterogeneity of multiple mitochondrial dysfunctions syndrome, see MMDS1 (605711).
Intellectual developmental disorder, autosomal dominant 72
MedGen UID:
1841248
Concept ID:
C5830612
Mental or Behavioral Dysfunction
Autosomal dominant intellectual developmental disorder-72 (MRD72) is characterized by developmental delay, predominant speech delay, autistic or attention-deficit/hyperactivity disorder features, overfriendliness, generalized hypotonia, overweight/obesity, and dysmorphic features (Cuinat et al., 2022).
Intellectual developmental disorder, autosomal dominant 73
MedGen UID:
1841272
Concept ID:
C5830636
Mental or Behavioral Dysfunction
Autosomal dominant intellectual developmental disorder-73 (MRD73) is a highly variable neurodevelopmental disorder characterized by impaired intellectual development that ranges from mild to severe, speech delay, behavioral abnormalities, and nonspecific dysmorphic facial features (Janssen et al., 2022).
Auriculocondylar syndrome 2B
MedGen UID:
1841300
Concept ID:
C5830664
Disease or Syndrome
ARCND2B is characterized by the typical features of auriculocondylar syndrome, including the pathognomonic question mark ears, consisting of a variable degree of clefting between the helix and earlobe, as well as hypoplasia of the mandibular condyle, temporomandibular joint abnormalities, micrognathia, microstomia, glossoptosis, and a round facial appearance with prominent cheeks. Patients have difficulty chewing, respiratory abnormalities, snoring, and obstructive and central apneas. In addition, they experience severe gastrointestinal problems, including feeding difficulties with failure to thrive, gastroesophageal reflux, and chronic constipation, and male patients show macropenis whereas female patients may exhibit clitoromegaly (summary by Leoni et al., 2016). Heterozygous mutation in the PLCB4 gene also causes an autosomal dominant form of auriculocondylar syndrome (see ARCND2A, 614669). For a discussion of genetic heterogeneity of auriculocondylar syndrome, see ARCND1 (602483).
Cranial dysinnervation disorder, congenital, with absent corneal reflex and developmental delay
MedGen UID:
1848439
Concept ID:
C5882675
Disease or Syndrome
Congenital cranial dysinnervation disorder with absent corneal reflex and developmental delay (CCDDRD) is an autosomal recessive disorder characterized by abnormal development of the proximal cranial sensory ganglia and nerves, mainly CN V (trigeminal nerve) and CN VIII (vestibulocochlear nerve). Affected individuals present at birth or in early infancy with corneal opacities due to absent blinking. Most patients also have sensorineural deafness associated with hypoplastic or malformed cochlea and hypoplasia or agenesis of CN VIII. Developmental delay with poor speech and autistic behavior are also present. Additional features may include expressionless face, feeding or chewing difficulties due to oromotor dysfunction, and dysmorphic facial features (Dupont et al., 2021; Sheth et al., 2023).
Neurodevelopmental disorder with impaired language, behavioral abnormalities, and dysmorphic facies
MedGen UID:
1847194
Concept ID:
C5882686
Disease or Syndrome
Neurodevelopmental disorder with impaired language, behavioral abnormalities, and dysmorphic facies (NEDLBF) is characterized by global developmental delay, speech delay, variably impaired intellectual development, behavioral abnormalities, and dysmorphic facial features. The phenotype and severity of the disorder is heterogeneous, ranging from borderline to severe. Brain imaging is usually normal. More variable additional features include early feeding difficulties, failure to thrive, short stature, mild visual impairment, hypotonia, seizures (particularly febrile), and distal skeletal defects of the hands and feet (Jia et al., 2022).
Neurodevelopmental disorder with language delay and variable cognitive abnormalities
MedGen UID:
1850358
Concept ID:
C5882689
Disease or Syndrome
Neurodevelopmental disorder with language delay and variable cognitive abnormalities (NEDLC) is a phenotypically heterogeneous neurologic disorder. Affected individuals may show early motor delay, speech and language delay, impaired intellectual development, learning disabilities, and/or behavioral abnormalities, although the severity and manifestations vary widely. Repetitive behavior and sleep difficulties are commonly present. More severe features include seizures, hypotonia, ocular abnormalities, dysmorphic features, and psychiatric comorbidities (Cediel et al., 2022).
Fliedner-Zweier syndrome
MedGen UID:
1845438
Concept ID:
C5882693
Disease or Syndrome
Fliedner-Zweier syndrome (FZS) is a neurodevelopmental disorder characterized by variable manifestations including mild intellectual disability, seizures, behavioral abnormalities, and various skeletal and structural anomalies (Fliedner et al., 2020).
Developmental delay, dysmorphic facies, and brain anomalies
MedGen UID:
1847857
Concept ID:
C5882698
Disease or Syndrome
Developmental delay, dysmorphic facies, and brain anomalies (DEVDFB) is characterized by global developmental delay with impaired intellectual development, speech delay, nonspecific dysmorphic facial features, hypotonia, and impaired overall growth with small head circumference. Most affected individuals have early-onset seizures that are variable in severity. Brain imaging typically shows hypoplasia of the corpus callosum and/or delayed myelination (Hiraide et al., 2021; Kuroda et al., 2023).
Developmental and epileptic encephalopathy 112
MedGen UID:
1845523
Concept ID:
C5882700
Disease or Syndrome
Developmental and epileptic encephalopathy-112 (DEE112) is an autosomal dominant disorder characterized by a wide range of seizure types, including focal and generalized seizures. Cognitive outcomes range from normal intellect to profound impairment (summary by Happ et al., 2023). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Developmental delay with or without epilepsy
MedGen UID:
1848555
Concept ID:
C5882702
Disease or Syndrome
Developmental delay with or without epilepsy (DEVEP) is a clinically heterogeneous neurodevelopmental disorder characterized by motor delay, speech delay, and variably impaired intellectual development apparent from infancy or early childhood. Hypotonia and behavioral abnormalities are common. About half of affected individuals develop various types of seizures that are not as severe as observed in the allelic disorder DEE5. In general, the phenotype is similar to but milder than DEE5. Some individuals with DEVEP have ataxia or nystagmus associated with cerebellar atrophy on brain imaging, indicating phenotypic overlap with the allelic disorder SPG91 (Morsy et al., 2023). In a study of 31 individuals with SPTAN1 mutations, Morsy et al. (2023) delineated 3 distinct phenotypic subgroups: DEE5; a milder phenotype of developmental delay with or without seizures (DEVEP); and pure or complicated spastic paraplegia/ataxia (SPG91). Syrbe et al. (2017) similarly emphasized the remarkably broad phenotypic spectrum of neurologic disorders associated with heterozygous SPTAN1 mutations in their cohort study.
Intellectual developmental disorder, autosomal recessive 80, with variant lissencephaly
MedGen UID:
1850178
Concept ID:
C5882733
Disease or Syndrome
Autosomal recessive intellectual developmental disorder-80 with variant lissencephaly (MRT80) is characterized by global developmental delay with mildly to moderately impaired intellectual development and behavioral abnormalities. Speech delay and motor abnormalities, such as hypotonia, may also be present. Brain imaging shows lissencephaly with pachygyria and mild cortical thickening in the frontotemporal lobes (Uctepe et al., 2024).
Polydactyly-macrocephaly syndrome
MedGen UID:
1847761
Concept ID:
C5882754
Disease or Syndrome
Polydactyly-macrocephaly syndrome (PDMCS) is characterized by postaxial polydactyly and progressive macrocephaly. Variable ocular anomalies have been observed, including microphthalmia and coloboma as well as delayed visual maturation. Neurodevelopmental anomalies are also present, including global developmental delay and autism or autistic traits, with prominent perivascular spaces on brain imaging (Harris et al., 2024).
Teebi hypertelorism syndrome 1
MedGen UID:
989457
Concept ID:
CN306405
Disease or Syndrome
Teebi hypertelorism syndrome-1 (TBHS1) is an autosomal dominant disorder characterized by hypertelorism with upslanting palpebral fissures, prominent forehead, broad and depressed nasal bridge with short nose, thick eyebrows, and widow's peak. Additional features include small broad hands with mild interdigital webbing and shawl scrotum. Umbilical malformations, cardiac defects, natal teeth, cleft lip/palate, congenital diaphragmatic hernia, and malformations of the central nervous system (ventriculomegaly, abnormal corpus callosum) have also been reported. Development is typically normal, although some patients with developmental delays have been reported (summary by Bhoj et al., 2015). Genetic Heterogeneity of Teebi Hypertelorism Syndrome Teebi hypertelorism syndrome-2 (TBHS2; 619736) is caused by mutation in the CDH11 gene (600023) on chromosome 16q21.
Hao-Fountain syndrome due to USP7 mutation
MedGen UID:
1054565
Concept ID:
CN377631
Disease or Syndrome

Professional guidelines

PubMed

Samanta D
Neuropediatrics 2020 Apr;51(2):135-145. Epub 2020 Feb 20 doi: 10.1055/s-0040-1701694. PMID: 32079034
Silva LM, Schalock M, Ayres R
Chin J Integr Med 2011 Jun;17(6):421-9. Epub 2011 Jun 10 doi: 10.1007/s11655-011-0635-0. PMID: 21660676
Olsson B, Rett A
Brain Dev 1985;7(3):281-9. doi: 10.1016/s0387-7604(85)80029-2. PMID: 4061759

Recent clinical studies

Etiology

Mai AS, Yau CE, Tseng FS, Foo QXJ, Wang DQ, Tan EK
Ann Clin Transl Neurol 2023 Apr;10(4):484-496. Epub 2023 Feb 4 doi: 10.1002/acn3.51736. PMID: 36738194Free PMC Article
Monteiro MA, Santos AAAD, Gomes LMM, Rito RVVF
Rev Paul Pediatr 2020;38:e2018262. Epub 2020 Mar 16 doi: 10.1590/1984-0462/2020/38/2018262. PMID: 32187297Free PMC Article
Nicolini C, Fahnestock M
Exp Neurol 2018 Jan;299(Pt A):217-227. Epub 2017 May 2 doi: 10.1016/j.expneurol.2017.04.017. PMID: 28472621
Pavăl D
Dev Neurosci 2017;39(5):355-360. Epub 2017 Jul 28 doi: 10.1159/000478725. PMID: 28750400
Good P
Clin Nutr ESPEN 2017 Feb;17:1-7. Epub 2016 Oct 20 doi: 10.1016/j.clnesp.2016.09.002. PMID: 28361738

Diagnosis

Good P
Clin Nutr ESPEN 2017 Feb;17:1-7. Epub 2016 Oct 20 doi: 10.1016/j.clnesp.2016.09.002. PMID: 28361738
Simms MD
Pediatr Clin North Am 2017 Feb;64(1):127-138. doi: 10.1016/j.pcl.2016.08.009. PMID: 27894440
Fakhoury M
Int J Dev Neurosci 2015 Jun;43:70-7. Epub 2015 Apr 8 doi: 10.1016/j.ijdevneu.2015.04.003. PMID: 25862937
Trachtman JN
Optometry 2008 Jul;79(7):391-6. doi: 10.1016/j.optm.2007.10.015. PMID: 18577496
Jure R, Rapin I, Tuchman RF
Dev Med Child Neurol 1991 Dec;33(12):1062-72. doi: 10.1111/j.1469-8749.1991.tb14828.x. PMID: 1778343

Therapy

Monteiro MA, Santos AAAD, Gomes LMM, Rito RVVF
Rev Paul Pediatr 2020;38:e2018262. Epub 2020 Mar 16 doi: 10.1590/1984-0462/2020/38/2018262. PMID: 32187297Free PMC Article
Samanta D
Neuropediatrics 2020 Apr;51(2):135-145. Epub 2020 Feb 20 doi: 10.1055/s-0040-1701694. PMID: 32079034
Pavăl D
Dev Neurosci 2017;39(5):355-360. Epub 2017 Jul 28 doi: 10.1159/000478725. PMID: 28750400
Robinson EB, Lichtenstein P, Anckarsäter H, Happé F, Ronald A
Proc Natl Acad Sci U S A 2013 Mar 26;110(13):5258-62. Epub 2013 Feb 19 doi: 10.1073/pnas.1211070110. PMID: 23431162Free PMC Article
Cave SF
Altern Ther Health Med 2008 Nov-Dec;14(6):54-7. PMID: 19043939

Prognosis

Nicolini C, Fahnestock M
Exp Neurol 2018 Jan;299(Pt A):217-227. Epub 2017 May 2 doi: 10.1016/j.expneurol.2017.04.017. PMID: 28472621
Pavăl D
Dev Neurosci 2017;39(5):355-360. Epub 2017 Jul 28 doi: 10.1159/000478725. PMID: 28750400
Roberts JE, Tonnsen B, Robinson A, Shinkareva SV
Am J Intellect Dev Disabil 2012 Mar;117(2):90-102. doi: 10.1352/1944-7558-117.2.90. PMID: 22515825Free PMC Article
Hatton DD, Hooper SR, Bailey DB, Skinner ML, Sullivan KM, Wheeler A
Am J Med Genet 2002 Mar 1;108(2):105-16. doi: 10.1002/ajmg.10216. PMID: 11857559
Jure R, Rapin I, Tuchman RF
Dev Med Child Neurol 1991 Dec;33(12):1062-72. doi: 10.1111/j.1469-8749.1991.tb14828.x. PMID: 1778343

Clinical prediction guides

Wong LC, Huang CH, Chou WY, Hsu CJ, Tsai WC, Lee WT
Autism Res 2023 May;16(5):953-966. Epub 2023 Mar 21 doi: 10.1002/aur.2916. PMID: 36942618
Mai AS, Yau CE, Tseng FS, Foo QXJ, Wang DQ, Tan EK
Ann Clin Transl Neurol 2023 Apr;10(4):484-496. Epub 2023 Feb 4 doi: 10.1002/acn3.51736. PMID: 36738194Free PMC Article
Nicolini C, Fahnestock M
Exp Neurol 2018 Jan;299(Pt A):217-227. Epub 2017 May 2 doi: 10.1016/j.expneurol.2017.04.017. PMID: 28472621
Pavăl D
Dev Neurosci 2017;39(5):355-360. Epub 2017 Jul 28 doi: 10.1159/000478725. PMID: 28750400
Horvath K, Perman JA
Curr Gastroenterol Rep 2002 Jun;4(3):251-8. doi: 10.1007/s11894-002-0071-6. PMID: 12010627

Recent systematic reviews

Monteiro MA, Santos AAAD, Gomes LMM, Rito RVVF
Rev Paul Pediatr 2020;38:e2018262. Epub 2020 Mar 16 doi: 10.1590/1984-0462/2020/38/2018262. PMID: 32187297Free PMC Article

Supplemental Content

Table of contents

    Clinical resources

    Practice guidelines

    • PubMed
      See practice and clinical guidelines in PubMed. The search results may include broader topics and may not capture all published guidelines. See the FAQ for details.
    • Bookshelf
      See practice and clinical guidelines in NCBI Bookshelf. The search results may include broader topics and may not capture all published guidelines. See the FAQ for details.

    Consumer resources

    Recent activity

    Your browsing activity is empty.

    Activity recording is turned off.

    Turn recording back on

    See more...