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Syndromic X-linked intellectual disability Lubs type(MRXSL)

MedGen UID:
337496
Concept ID:
C1846058
Disease or Syndrome
Synonyms: INTELLECTUAL DEVELOPMENTAL DISORDER, X-LINKED, SYNDROMIC, LUBS TYPE; Lubs X-linked mental retardation syndrome; MECP2 duplication syndrome; Mental retardation, X-linked, Lubs type; MENTAL RETARDATION, X-LINKED, WITH RECURRENT RESPIRATORY INFECTIONS; MRXSL; XLMR syndrome, Lubs type
SNOMED CT: Methyl-CpG (cytosine phosphate guanine) binding protein-2 duplication syndrome (702816000); MECP2 duplication syndrome (702816000); Methyl-cytosine phosphate guanine binding protein-2 duplication syndrome (702816000); Lubs X-linked mental retardation syndrome (702816000); Lubs X-linked intellectual disability syndrome (702816000); Proximal Xq28 duplication syndrome (702816000)
 
Gene (location): MECP2 (Xq28)
 
Monarch Initiative: MONDO:0010283
OMIM®: 300260
Orphanet: ORPHA1762

Disease characteristics

Excerpted from the GeneReview: MECP2 Duplication 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. [from GeneReviews]
Authors:
Hilde Van Esch   view full author information

Additional descriptions

From OMIM
X-linked Lubs-type syndromic intellectual developmental disorder (MRXSL) is a neurodevelopmental disorder characterized by severely to profoundly impaired intellectual development, infantile hypotonia, mild dysmorphic features, poor speech development, autistic features, seizures, progressive spasticity, and recurrent infections. Only males are affected, although female carriers may have some mild neuropsychiatric features, such as anxiety. Submicroscopic Xq28 duplications encompassing MECP2 are considered nonrecurrent events, because the breakpoint locations and rearrangement sizes vary among affected individuals (summary by Ramocki et al., 2010).  http://www.omim.org/entry/300260
From MedlinePlus Genetics
MECP2 duplication syndrome is a condition that occurs almost exclusively in males and is characterized by moderate to severe intellectual disability. Most people with this condition also have weak muscle tone in infancy, feeding difficulties, poor or absent speech, or muscle stiffness (rigidity). Individuals with MECP2 duplication syndrome have delayed development of motor skills such as sitting and walking. About half of individuals have seizures, often of the tonic-clonic type. This type of seizure involves a loss of consciousness, muscle rigidity, and convulsions and may not respond to medication. Some affected individuals experience the loss of previously acquired skills (developmental regression). Approximately half of individuals learn to walk, and about one-third of people with this condition require assistance when walking. Many individuals with MECP2 duplication syndrome have recurrent respiratory tract infections. These respiratory infections are a major cause of death in affected individuals, with only half surviving past age 25.  https://medlineplus.gov/genetics/condition/mecp2-duplication-syndrome

Clinical features

From HPO
Cryptorchidism
MedGen UID:
8192
Concept ID:
C0010417
Congenital Abnormality
Cryptorchidism, or failure of testicular descent, is a common human congenital abnormality with a multifactorial etiology that likely reflects the involvement of endocrine, environmental, and hereditary factors. Cryptorchidism can result in infertility and increases risk for testicular tumors. Testicular descent from abdomen to scrotum occurs in 2 distinct phases: the transabdominal phase and the inguinoscrotal phase (summary by Gorlov et al., 2002).
Hypospadias
MedGen UID:
163083
Concept ID:
C0848558
Congenital Abnormality
Abnormal position of urethral meatus on the ventral penile shaft (underside) characterized by displacement of the urethral meatus from the tip of the glans penis to the ventral surface of the penis, scrotum, or perineum.
2-3 toe cutaneous syndactyly
MedGen UID:
98470
Concept ID:
C0432040
Congenital Abnormality
Short foot
MedGen UID:
376415
Concept ID:
C1848673
Finding
A measured foot length that is more than 2 SD below the mean for a newborn of 27 - 41 weeks gestation, or foot that is less than the 3rd centile for individuals from birth to 16 years of age (objective). Alternatively, a foot that appears disproportionately short (subjective).
Clinodactyly of the 5th finger
MedGen UID:
340456
Concept ID:
C1850049
Congenital Abnormality
Clinodactyly refers to a bending or curvature of the fifth finger in the radial direction (i.e., towards the 4th finger).
Growth delay
MedGen UID:
99124
Concept ID:
C0456070
Pathologic Function
A deficiency or slowing down of growth pre- and postnatally.
Decreased body weight
MedGen UID:
1806755
Concept ID:
C5574742
Finding
Abnormally low body weight.
Dysphagia
MedGen UID:
41440
Concept ID:
C0011168
Disease or Syndrome
Difficulty in swallowing.
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.
Chronic constipation
MedGen UID:
98325
Concept ID:
C0401149
Sign or Symptom
Constipation for longer than three months with fewer than 3 bowel movements per week, straining, lumpy or hard stools, and a sensation of anorectal obstruction or incomplete defecation.
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.
Macrotia
MedGen UID:
488785
Concept ID:
C0152421
Congenital Abnormality
Median longitudinal ear length greater than two standard deviations above the mean and median ear width greater than two standard deviations above the mean (objective); or, apparent increase in length and width of the pinna (subjective).
Low-set ears
MedGen UID:
65980
Concept ID:
C0239234
Congenital Abnormality
Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear.
Anxiety
MedGen UID:
1613
Concept ID:
C0003467
Finding
Intense feelings of nervousness, tension, or panic often arise in response to interpersonal stresses. There is worry about the negative effects of past unpleasant experiences and future negative possibilities. Individuals may feel fearful, apprehensive, or threatened by uncertainty, and they may also have fears of falling apart or losing control.
Bruxism
MedGen UID:
676
Concept ID:
C0006325
Mental or Behavioral Dysfunction
Bruxism is characterized by the grinding of the teeth including the clenching of the jaw and typically occur during sleep, but also can occur while the affected individual is awake.
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).
Chorea
MedGen UID:
3420
Concept ID:
C0008489
Disease or Syndrome
Chorea (Greek for 'dance') refers to widespread arrhythmic involuntary movements of a forcible, jerky and restless fashion. It is a random-appearing sequence of one or more discrete involuntary movements or movement fragments. Movements appear random because of variability in timing, duration or location. Each movement may have a distinct start and end. However, movements may be strung together and thus may appear to flow randomly from one muscle group to another. Chorea can involve the trunk, neck, face, tongue, and extremities.
Depression
MedGen UID:
4229
Concept ID:
C0011581
Mental or Behavioral Dysfunction
Frequently experiencing feelings of being down, miserable, and/or hopeless; struggling to recover from these moods; having a pessimistic outlook on the future; feeling a pervasive sense of shame; having a low self-worth; experiencing thoughts of suicide and engaging in suicidal behavior.
Hostility
MedGen UID:
5639
Concept ID:
C0020039
Mental Process
Persistent or frequent feelings of anger; anger or irritability in response to minor slights and insults.
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.
Intellectual disability, severe
MedGen UID:
48638
Concept ID:
C0036857
Mental or Behavioral Dysfunction
Severe mental retardation is defined as an intelligence quotient (IQ) in the range of 20-34.
Sleep abnormality
MedGen UID:
52372
Concept ID:
C0037317
Finding
An abnormal pattern in the quality, quantity, or characteristics of sleep.
Status epilepticus
MedGen UID:
11586
Concept ID:
C0038220
Disease or Syndrome
Status epilepticus is a type of prolonged seizure resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms which lead to abnormally prolonged seizures (after time point t1). It is a condition that can have long-term consequences (after time point t2), including neuronal death, neuronal injury, and alteration of neuronal networks, depending on the type and duration of seizures.
Motor stereotypies
MedGen UID:
21318
Concept ID:
C0038271
Individual Behavior
Use of the same abnormal action in response to certain triggers or at random. They may be used as a way to regulate one's internal state but must otherwise have no apparent functional purpose.
Delayed ability to walk
MedGen UID:
66034
Concept ID:
C0241726
Finding
A failure to achieve the ability to walk at an appropriate developmental stage. Most children learn to walk in a series of stages, and learn to walk short distances independently between 12 and 15 months.
Tonic seizure
MedGen UID:
82855
Concept ID:
C0270844
Disease or Syndrome
A tonic seizure is a type of motor seizure characterized by unilateral or bilateral limb stiffening or elevation, often with neck stiffening.
Pain insensitivity
MedGen UID:
488855
Concept ID:
C0344307
Finding
Inability to perceive painful stimuli.
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.
Autistic behavior
MedGen UID:
163547
Concept ID:
C0856975
Mental or Behavioral Dysfunction
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.
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
Reduced eye contact
MedGen UID:
303190
Concept ID:
C1445953
Finding
A reduced frequency or duration of eye contact.
Developmental regression
MedGen UID:
324613
Concept ID:
C1836830
Disease or Syndrome
Loss of developmental skills, as manifested by loss of developmental milestones.
Severe global developmental delay
MedGen UID:
332436
Concept ID:
C1837397
Finding
A severe delay in the achievement of motor or mental milestones in the domains of development of a child.
Absent speech
MedGen UID:
340737
Concept ID:
C1854882
Finding
Complete lack of development of speech and language abilities.
Progressive spasticity
MedGen UID:
347171
Concept ID:
C1859520
Finding
Spasticity that increases in degree with time.
Repetitive compulsive behavior
MedGen UID:
409891
Concept ID:
C1969697
Mental or Behavioral Dysfunction
Generalized non-motor (absence) seizure
MedGen UID:
1385688
Concept ID:
C4316903
Disease or Syndrome
A generalized non-motor (absence) seizure is a type of a type of dialeptic seizure that is of electrographically generalized onset. It is a generalized seizure characterized by an interruption of activities, a blank stare, and usually the person will be unresponsive when spoken to. Any ictal motor phenomena are minor in comparison to these non-motor features.
Delayed ability to sit
MedGen UID:
1368737
Concept ID:
C4476710
Finding
A failure to achieve the ability to sit at an appropriate developmental stage. Most children sit with support at 6 months of age and sit steadily without support at 9 months of age.
Delayed ability to roll over
MedGen UID:
1718874
Concept ID:
C5397980
Finding
Delayed achievement of the ability to roll front to back and back to front.
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.
Rigidity
MedGen UID:
7752
Concept ID:
C0026837
Sign or Symptom
Continuous involuntary sustained muscle contraction. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity.
Brachycephaly
MedGen UID:
113165
Concept ID:
C0221356
Congenital Abnormality
An abnormality of skull shape characterized by a decreased anterior-posterior diameter. That is, a cephalic index greater than 81%. Alternatively, an apparently shortened anteroposterior dimension (length) of the head compared to width.
Facial hypotonia
MedGen UID:
336889
Concept ID:
C1845251
Finding
Reduced muscle tone of a muscle that is innervated by the facial nerve (the seventh cranial nerve).
Axial hypotonia
MedGen UID:
342959
Concept ID:
C1853743
Finding
Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk.
Malar flattening
MedGen UID:
347616
Concept ID:
C1858085
Finding
Underdevelopment of the malar prominence of the jugal bone (zygomatic bone in mammals), appreciated in profile, frontal view, and/or by palpation.
Infantile muscular hypotonia
MedGen UID:
395993
Concept ID:
C1860834
Finding
Muscular hypotonia (abnormally low muscle tone) manifesting in infancy.
Macrocephaly
MedGen UID:
745757
Concept ID:
C2243051
Finding
Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium.
Microcephaly
MedGen UID:
1644158
Concept ID:
C4551563
Finding
Head circumference below 2 standard deviations below the mean for age and gender.
Recurrent respiratory infections
MedGen UID:
812812
Concept ID:
C3806482
Finding
An increased susceptibility to respiratory infections as manifested by a history of recurrent respiratory infections.
Recurrent infections
MedGen UID:
65998
Concept ID:
C0239998
Finding
Increased susceptibility to infections.
Severe infection
MedGen UID:
1700844
Concept ID:
C5139167
Disease or Syndrome
A type of infection that is regarded as a sign of a pathological susceptibility to infection because of unusual severity or intensity of the infection.
Drooling
MedGen UID:
8484
Concept ID:
C0013132
Finding
Habitual flow of saliva out of the mouth.
Narrow mouth
MedGen UID:
44435
Concept ID:
C0026034
Congenital Abnormality
Distance between the commissures of the mouth more than 2 SD below the mean. Alternatively, an apparently decreased width of the oral aperture (subjective).
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.
Epicanthus
MedGen UID:
151862
Concept ID:
C0678230
Congenital Abnormality
Epicanthus is a condition in which a fold of skin stretches from the upper to the lower eyelid, partially covering the inner canthus. Usher (1935) noted that epicanthus is a normal finding in the fetus of all races. Epicanthus also occurs in association with hereditary ptosis (110100).
Depressed nasal bridge
MedGen UID:
373112
Concept ID:
C1836542
Finding
Posterior positioning of the nasal root in relation to the overall facial profile for age.
Tented upper lip vermilion
MedGen UID:
326574
Concept ID:
C1839767
Finding
Triangular appearance of the oral aperture with the apex in the midpoint of the upper vermilion and the lower vermilion forming the base.
Anteverted nares
MedGen UID:
326648
Concept ID:
C1840077
Finding
Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip).
Widely spaced teeth
MedGen UID:
337093
Concept ID:
C1844813
Finding
Increased spaces (diastemata) between most of the teeth in the same dental arch.
Wide nasal bridge
MedGen UID:
341441
Concept ID:
C1849367
Finding
Increased breadth of the nasal bridge (and with it, the nasal root).
Midface retrusion
MedGen UID:
339938
Concept ID:
C1853242
Anatomical Abnormality
Posterior positions and/or vertical shortening of the infraorbital and perialar regions, or increased concavity of the face and/or reduced nasolabial angle.
Prominent nasal bridge
MedGen UID:
343051
Concept ID:
C1854113
Finding
Anterior positioning of the nasal root in comparison to the usual positioning for age.
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).

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVSyndromic X-linked intellectual disability Lubs type

Recent clinical studies

Etiology

Xia S, Xu HT
Neurosci Bull 2022 Jun;38(6):591-606. Epub 2022 Feb 11 doi: 10.1007/s12264-022-00824-x. PMID: 35147909Free PMC Article
Marafi D, Suter B, Schultz R, Glaze D, Pavlik VN, Goldman AM
Neurology 2019 Jan 8;92(2):e108-e114. Epub 2018 Dec 14 doi: 10.1212/WNL.0000000000006742. PMID: 30552298Free PMC Article

Diagnosis

Marafi D, Suter B, Schultz R, Glaze D, Pavlik VN, Goldman AM
Neurology 2019 Jan 8;92(2):e108-e114. Epub 2018 Dec 14 doi: 10.1212/WNL.0000000000006742. PMID: 30552298Free PMC Article

Prognosis

Marafi D, Suter B, Schultz R, Glaze D, Pavlik VN, Goldman AM
Neurology 2019 Jan 8;92(2):e108-e114. Epub 2018 Dec 14 doi: 10.1212/WNL.0000000000006742. PMID: 30552298Free PMC Article
Jin H, May M, Tranebjaerg L, Kendall E, Fontán G, Jackson J, Subramony SH, Arena F, Lubs H, Smith S, Stevenson R, Schwartz C, Vetrie D
Nat Genet 1996 Oct;14(2):177-80. doi: 10.1038/ng1096-177. PMID: 8841189

Clinical prediction guides

Lotti F, Geronzi U, Grosso S
Brain Dev 2019 May;41(5):456-459. Epub 2019 Jan 11 doi: 10.1016/j.braindev.2018.12.008. PMID: 30642617
Jin H, May M, Tranebjaerg L, Kendall E, Fontán G, Jackson J, Subramony SH, Arena F, Lubs H, Smith S, Stevenson R, Schwartz C, Vetrie D
Nat Genet 1996 Oct;14(2):177-80. doi: 10.1038/ng1096-177. PMID: 8841189

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