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Intellectual disability, autosomal dominant 56(MRD56)

MedGen UID:
1638835
Concept ID:
C4693389
Mental or Behavioral Dysfunction
Synonyms: INTELLECTUAL DEVELOPMENTAL DISORDER, AUTOSOMAL DOMINANT 56; MENTAL RETARDATION, AUTOSOMAL DOMINANT 56
 
Gene (location): CLTC (17q23.1)
 
Monarch Initiative: MONDO:0030922
OMIM®: 617854

Clinical features

From HPO
Feeding difficulties
MedGen UID:
65429
Concept ID:
C0232466
Finding
Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it.
Gastroesophageal reflux
MedGen UID:
1368658
Concept ID:
C4317146
Finding
A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter.
Sensorineural hearing loss disorder
MedGen UID:
9164
Concept ID:
C0018784
Disease or Syndrome
A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.
Protruding ear
MedGen UID:
343309
Concept ID:
C1855285
Finding
Angle formed by the plane of the ear and the mastoid bone greater than the 97th centile for age (objective); or, outer edge of the helix more than 2 cm from the mastoid at the point of maximum distance (objective).
Cerebellar ataxia
MedGen UID:
849
Concept ID:
C0007758
Disease or Syndrome
Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly).
Dystonic disorder
MedGen UID:
3940
Concept ID:
C0013421
Sign or Symptom
An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk.
Impulsivity
MedGen UID:
43850
Concept ID:
C0021125
Mental or Behavioral Dysfunction
Acting on the spur of the moment in response to immediate stimuli; acting on a momentary basis without a plan or consideration of outcomes; having difficulty establishing or following plans; experiencing a sense of urgency and engaging in self-harming behavior when under emotional distress.
Spasticity
MedGen UID:
7753
Concept ID:
C0026838
Sign or Symptom
A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes.
Myoclonus
MedGen UID:
10234
Concept ID:
C0027066
Finding
Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements.
Seizure
MedGen UID:
20693
Concept ID:
C0036572
Sign or Symptom
A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.
Hypokinesia
MedGen UID:
39223
Concept ID:
C0086439
Finding
Abnormally diminished motor activity. In contrast to paralysis, hypokinesia is not characterized by a lack of motor strength, but rather by a poverty of movement. The typical habitual movements (e.g., folding the arms, crossing the legs) are reduced in frequency.
Paraparesis
MedGen UID:
113150
Concept ID:
C0221166
Sign or Symptom
Weakness or partial paralysis in the lower limbs.
Bradykinesia
MedGen UID:
115925
Concept ID:
C0233565
Sign or Symptom
Bradykinesia literally means slow movement, and is used clinically to denote a slowness in the execution of movement (in contrast to hypokinesia, which is used to refer to slowness in the initiation of movement).
Clumsiness
MedGen UID:
66690
Concept ID:
C0233844
Sign or Symptom
Lack of physical coordination resulting in an abnormal tendency to drop items or bump into objects.
Short attention span
MedGen UID:
82652
Concept ID:
C0262630
Finding
Reduced attention span characterized by distractibility and impulsivity.
Bradyphrenia
MedGen UID:
640666
Concept ID:
C0554976
Mental or Behavioral Dysfunction
Abnormal slowness of thought processes.
Global developmental delay
MedGen UID:
107838
Concept ID:
C0557874
Finding
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Inability to walk
MedGen UID:
107860
Concept ID:
C0560046
Finding
Incapability to ambulate.
Broad-based gait
MedGen UID:
167799
Concept ID:
C0856863
Finding
An abnormal gait pattern in which persons stand and walk with their feet spaced widely apart. This is often a component of cerebellar ataxia.
Attention deficit hyperactivity disorder
MedGen UID:
220387
Concept ID:
C1263846
Mental or Behavioral Dysfunction
Attention-deficit/hyperactivity disorder (ADHD) is a behavioral disorder that typically begins in childhood and is characterized by a short attention span (inattention), an inability to be calm and stay still (hyperactivity), and poor impulse control (impulsivity). Some people with ADHD have problems with only inattention or with hyperactivity and impulsivity, but most have problems related to all three features.\n\nIn people with ADHD, the characteristic behaviors are frequent and severe enough to interfere with the activities of daily living such as school, work, and relationships with others. Because of an inability to stay focused on tasks, people with inattention may be easily distracted, forgetful, avoid tasks that require sustained attention, have difficulty organizing tasks, or frequently lose items.\n\nHyperactivity is usually shown by frequent movement. Individuals with this feature often fidget or tap their foot when seated, leave their seat when it is inappropriate to do so (such as in the classroom), or talk a lot and interrupt others.\n\nImpulsivity can result in hasty actions without thought for the consequences. Individuals with poor impulse control may have difficulty waiting for their turn, deferring to others, or considering their actions before acting.\n\nIn most affected individuals, ADHD continues throughout life, but in about one-third of individuals, signs and symptoms of ADHD go away by adulthood.\n\nMore than two-thirds of all individuals with ADHD have additional conditions, including insomnia, mood or anxiety disorders, learning disorders, or substance use disorders. Affected individuals may also have autism spectrum disorder, which is characterized by impaired communication and social interaction, or Tourette syndrome, which is a disorder characterized by repetitive and involuntary movements or noises called tics.
Lower limb spasticity
MedGen UID:
220865
Concept ID:
C1271100
Finding
Spasticity (velocity-dependent increase in tonic stretch reflexes with increased muscle tone and hyperexcitable tendon reflexes) in the muscles of the lower limbs, hips, and pelvis
Delayed myelination
MedGen UID:
224820
Concept ID:
C1277241
Finding
Delayed myelination.
Pontocerebellar atrophy
MedGen UID:
381261
Concept ID:
C1853766
Disease or Syndrome
Atrophy affecting the pons and the cerebellum.
Absent speech
MedGen UID:
340737
Concept ID:
C1854882
Finding
Complete lack of development of speech and language abilities.
Lateral ventricle dilatation
MedGen UID:
383904
Concept ID:
C1856409
Pathologic Function
Intellectual disability
MedGen UID:
811461
Concept ID:
C3714756
Mental or Behavioral Dysfunction
Intellectual disability, previously referred to as mental retardation, is characterized by subnormal intellectual functioning that occurs during the developmental period. It is defined by an IQ score below 70.
Delayed CNS myelination
MedGen UID:
867393
Concept ID:
C4021758
Anatomical Abnormality
Delayed myelination in the central nervous system.
Oromotor apraxia
MedGen UID:
867468
Concept ID:
C4021845
Disease or Syndrome
Oral-motor apraxia is the inability to volitionally sequence oral movements of the speech structure for nonspeech tasks in the absence of neuromuscular deficits such as paralysis or muscle weakness. Oral-motor apraxia is diagnosed when, despite intact sensory motor function an individual is unable to use these effector systems under voluntary control.
Reduced social responsiveness
MedGen UID:
868342
Concept ID:
C4022736
Finding
A reduced ability to participate in the back-and-forth flow of social interaction appropriate to culture and developmental level, which is normally characterized by an influence of the behavior of one person on the behavior of another person. This results in difficulty interacting with others through emotional, physical, or verbal communication.
Thin corpus callosum
MedGen UID:
1785336
Concept ID:
C5441562
Anatomical Abnormality
An abnormally thin corpus callous, due to atrophy, hypoplasia or agenesis. This term is intended to be used in situations where it is not known if thinning of the corpus callosum (for instance, as visualized by magnetic resonance tomography) is due to abnormal development (e.g. a leukodystrophy) or atrophy following normal development (e.g. neurodegeneration).
Hypotonia
MedGen UID:
10133
Concept ID:
C0026827
Finding
Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.
Secondary microcephaly
MedGen UID:
608952
Concept ID:
C0431352
Finding
Head circumference which falls below 2 standard deviations below the mean for age and gender because of insufficient head growth after birth.
Open mouth
MedGen UID:
116104
Concept ID:
C0240379
Finding
A facial appearance characterized by a permanently or nearly permanently opened mouth.
High palate
MedGen UID:
66814
Concept ID:
C0240635
Congenital Abnormality
Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective).
Upslanted palpebral fissure
MedGen UID:
98390
Concept ID:
C0423109
Finding
The palpebral fissure inclination is more than two standard deviations above the mean for age (objective); or, the inclination of the palpebral fissure is greater than typical for age.
Hypomimic face
MedGen UID:
208827
Concept ID:
C0813217
Finding
A reduced degree of motion of the muscles beneath the skin of the face, often associated with reduced facial crease formation.
Long philtrum
MedGen UID:
351278
Concept ID:
C1865014
Finding
Distance between nasal base and midline upper lip vermilion border more than 2 SD above the mean. Alternatively, an apparently increased distance between nasal base and midline upper lip vermilion border.
Thin upper lip vermilion
MedGen UID:
355352
Concept ID:
C1865017
Finding
Height of the vermilion of the upper lip in the midline more than 2 SD below the mean. Alternatively, an apparently reduced height of the vermilion of the upper lip in the frontal view (subjective).
Ptosis
MedGen UID:
2287
Concept ID:
C0005745
Disease or Syndrome
The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective).
Visual impairment
MedGen UID:
777085
Concept ID:
C3665347
Finding
Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery.

Professional guidelines

PubMed

Valverde de Morales HG, Wang HV, Garber K, Cheng X, Corces VG, Li H
Am J Med Genet A 2023 Mar;191(3):718-729. Epub 2022 Dec 1 doi: 10.1002/ajmg.a.63065. PMID: 36454652Free PMC Article
Lin L, Zhang Y, Pan H, Wang J, Qi Y, Ma Y
Orphanet J Rare Dis 2020 Nov 11;15(1):317. doi: 10.1186/s13023-020-01599-y. PMID: 33176815Free PMC Article

Recent clinical studies

Etiology

Pena JLB, Melo FJ, Santos WC, Moura ICG, Nakashima GP, Freitas NC, Sternick EB
Arq Bras Cardiol 2022 Dec;119(6):902-909. doi: 10.36660/abc.20210801. PMID: 36417616Free PMC Article
Parenti I, Lehalle D, Nava C, Torti E, Leitão E, Person R, Mizuguchi T, Matsumoto N, Kato M, Nakamura K, de Man SA, Cope H, Shashi V; Undiagnosed Diseases Network, Friedman J, Joset P, Steindl K, Rauch A, Muffels I, van Hasselt PM, Petit F, Smol T, Le Guyader G, Bilan F, Sorlin A, Vitobello A, Philippe C, van de Laar IMBH, van Slegtenhorst MA, Campeau PM, Au PYB, Nakashima M, Saitsu H, Yamamoto T, Nomura Y, Louie RJ, Lyons MJ, Dobson A, Plomp AS, Motazacker MM, Kaiser FJ, Timberlake AT, Fuchs SA, Depienne C, Mignot C
Hum Genet 2021 Jul;140(7):1109-1120. Epub 2021 May 4 doi: 10.1007/s00439-021-02283-2. PMID: 33944996Free PMC Article
Robert A, Leroy V, Riquet A, Gogneaux L, Boutry N, Avni FE
Radiol Med 2016 May;121(5):402-8. Epub 2015 Jul 29 doi: 10.1007/s11547-015-0572-7. PMID: 26219723
Sammour ZM, Gomes CM, de Bessa J Jr, Pinheiro MS, Kim CA, Hisano M, Bruschini H, Srougi M
J Pediatr Urol 2014 Oct;10(5):804-9. Epub 2014 Feb 13 doi: 10.1016/j.jpurol.2014.01.013. PMID: 24582571
Castori M, Valiante M, Pascolini G, Leuzzi V, Pizzuti A, Grammatico P
Eur J Med Genet 2013 Oct;56(10):570-6. Epub 2013 Aug 27 doi: 10.1016/j.ejmg.2013.08.004. PMID: 23994350

Diagnosis

Karimi K, Mol MO, Haghshenas S, Relator R, Levy MA, Kerkhof J, McConkey H, Brooks A, Zonneveld-Huijssoon E, Gerkes EH, Tedder ML, Vissers L, Salzano E, Piccione M, Asaftei SD, Carli D, Mussa A, Shukarova-Angelovska E, Trajkova S, Brusco A, Merla G, Alders MM, Bouman A, Sadikovic B
Genet Med 2024 Mar;26(3):101041. Epub 2023 Dec 3 doi: 10.1016/j.gim.2023.101041. PMID: 38054406
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Arq Neuropsiquiatr 2021 Nov;79(11):950-956. doi: 10.1590/0004-282X-ANP-2020-0450. PMID: 34816986
Robert A, Leroy V, Riquet A, Gogneaux L, Boutry N, Avni FE
Radiol Med 2016 May;121(5):402-8. Epub 2015 Jul 29 doi: 10.1007/s11547-015-0572-7. PMID: 26219723
Sammour ZM, Gomes CM, de Bessa J Jr, Pinheiro MS, Kim CA, Hisano M, Bruschini H, Srougi M
J Pediatr Urol 2014 Oct;10(5):804-9. Epub 2014 Feb 13 doi: 10.1016/j.jpurol.2014.01.013. PMID: 24582571

Therapy

Hwang SK, Lee JH, Yang JE, Lim CS, Lee JA, Lee YS, Lee K, Kaang BK
Mol Brain 2016 May 23;9(1):56. doi: 10.1186/s13041-016-0222-6. PMID: 27216612Free PMC Article
Matevosyan NR
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Prognosis

Cheng C, Yang F, Zhao S, Chen X
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Orphanet J Rare Dis 2020 Nov 11;15(1):317. doi: 10.1186/s13023-020-01599-y. PMID: 33176815Free PMC Article
Hennekam RC, Stevens CA, Van de Kamp JJ
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Clinical prediction guides

Cheng C, Yang F, Zhao S, Chen X
BMC Med Genomics 2023 Dec 18;16(1):331. doi: 10.1186/s12920-023-01778-3. PMID: 38111042Free PMC Article
Kutkowska-Kaźmierczak A, Boczar M, Kalka E, Castañeda J, Klapecki J, Pietrzyk A, Barczyk A, Malinowska O, Landowska A, Gambin T, Kowalczyk K, Wiśniowiecka-Kowalnik B, Smyk M, Dawidziuk M, Niepokój K, Paczkowska M, Szyld P, Lipska-Ziętkiewicz B, Szczałuba K, Kostyk E, Runge A, Rutkowska K, Płoski R, Nowakowska B, Bal J, Obersztyn E, Gos M
Genes (Basel) 2021 Aug 17;12(8) doi: 10.3390/genes12081257. PMID: 34440431Free PMC Article
Parenti I, Lehalle D, Nava C, Torti E, Leitão E, Person R, Mizuguchi T, Matsumoto N, Kato M, Nakamura K, de Man SA, Cope H, Shashi V; Undiagnosed Diseases Network, Friedman J, Joset P, Steindl K, Rauch A, Muffels I, van Hasselt PM, Petit F, Smol T, Le Guyader G, Bilan F, Sorlin A, Vitobello A, Philippe C, van de Laar IMBH, van Slegtenhorst MA, Campeau PM, Au PYB, Nakashima M, Saitsu H, Yamamoto T, Nomura Y, Louie RJ, Lyons MJ, Dobson A, Plomp AS, Motazacker MM, Kaiser FJ, Timberlake AT, Fuchs SA, Depienne C, Mignot C
Hum Genet 2021 Jul;140(7):1109-1120. Epub 2021 May 4 doi: 10.1007/s00439-021-02283-2. PMID: 33944996Free PMC Article
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Eur J Med Genet 2013 Oct;56(10):570-6. Epub 2013 Aug 27 doi: 10.1016/j.ejmg.2013.08.004. PMID: 23994350
Cossec JC, Lavaur J, Berman DE, Rivals I, Hoischen A, Stora S, Ripoll C, Mircher C, Grattau Y, Olivomarin JC, de Chaumont F, Lecourtois M, Antonarakis SE, Veltman JA, Delabar JM, Duyckaerts C, Di Paolo G, Potier MC
Hum Mol Genet 2012 Jul 15;21(14):3156-72. Epub 2012 Apr 17 doi: 10.1093/hmg/dds142. PMID: 22511594Free PMC Article

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