U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Syndromic X-linked intellectual disability Hedera type(MRXSH)

MedGen UID:
337257
Concept ID:
C1845543
Disease or Syndrome
Synonyms: INTELLECTUAL DEVELOPMENTAL DISORDER, X-LINKED, SYNDROMIC, HEDERA TYPE; MRXSH; X-Linked Mental Retardation with Epilepsy
SNOMED CT: X-linked intellectual disability Hedera type (726727003)
Modes of inheritance:
X-linked recessive inheritance
MedGen UID:
375779
Concept ID:
C1845977
Finding
Source: Orphanet
A mode of inheritance that is observed for recessive traits related to a gene encoded on the X chromosome. In the context of medical genetics, X-linked recessive disorders manifest in males (who have one copy of the X chromosome and are thus hemizygotes), but generally not in female heterozygotes who have one mutant and one normal allele.
 
Gene (location): ATP6AP2 (Xp11.4)
 
Monarch Initiative: MONDO:0010319
OMIM®: 300423
Orphanet: ORPHA93952

Definition

The Hedera type of X-linked syndromic intellectual developmental disorder (MRXSH) is characterized by global developmental delay apparent from infancy and progressive neurologic decline with abnormal movements, spasticity, and seizures. Brain imaging shows volume loss of cortical white and gray matter, thin corpus callosum, and myelination defects, consistent with a neurodegenerative process. Only males are affected (summary by Hirose et al., 2019). [from OMIM]

Clinical features

From HPO
Apraxia
MedGen UID:
8166
Concept ID:
C0003635
Mental or Behavioral Dysfunction
A defect in the understanding of complex motor commands and in the execution of certain learned movements, i.e., deficits in the cognitive components of learned movements.
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.
Babinski sign
MedGen UID:
19708
Concept ID:
C0034935
Finding
Upturning of the big toe (and sometimes fanning of the other toes) in response to stimulation of the sole of the foot. If the Babinski sign is present it can indicate damage to the corticospinal tract.
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.
Falls
MedGen UID:
39084
Concept ID:
C0085639
Finding
A sudden movement downward, usually resulting in injury.
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).
Action tremor
MedGen UID:
65875
Concept ID:
C0234376
Sign or Symptom
A tremor present when the limbs are active, either when outstretched in a certain position or throughout a voluntary movement.
Slurred speech
MedGen UID:
65885
Concept ID:
C0234518
Finding
Abnormal coordination of muscles involved in speech.
Cerebral atrophy
MedGen UID:
116012
Concept ID:
C0235946
Disease or Syndrome
Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum.
Parkinsonian disorder
MedGen UID:
66079
Concept ID:
C0242422
Disease or Syndrome
Characteristic neurologic anomaly resulting from degeneration of dopamine-generating cells in the substantia nigra, a region of the midbrain, characterized clinically by shaking, rigidity, slowness of movement and difficulty with walking and gait.
Hypoplasia of the corpus callosum
MedGen UID:
138005
Concept ID:
C0344482
Congenital Abnormality
Underdevelopment of the corpus callosum.
Delayed speech and language development
MedGen UID:
105318
Concept ID:
C0454644
Finding
A degree of language development that is significantly below the norm for a child of a specified age.
Bilateral tonic-clonic seizure
MedGen UID:
141670
Concept ID:
C0494475
Sign or Symptom
A bilateral tonic-clonic seizure is a seizure defined by a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase.
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.
Gait disturbance
MedGen UID:
107895
Concept ID:
C0575081
Finding
The term gait disturbance can refer to any disruption of the ability to walk.
Hyporeflexia
MedGen UID:
195967
Concept ID:
C0700078
Finding
Reduction of neurologic reflexes such as the knee-jerk reaction.
Cerebellar atrophy
MedGen UID:
196624
Concept ID:
C0740279
Disease or Syndrome
Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event.
Agraphesthesia
MedGen UID:
488967
Concept ID:
C1328618
Mental or Behavioral Dysfunction
Impaired ability to recognize letters or numbers drawn by an examiner's fingertip on the patient's skin (the patients eyes are closed or covered throughout this examination).
Motor delay
MedGen UID:
381392
Concept ID:
C1854301
Finding
A type of Developmental delay characterized by a delay in acquiring motor skills.
Impaired tandem gait
MedGen UID:
476998
Concept ID:
C3275367
Finding
Reduced ability to walk in a straight line while placing the feet heel to toe.
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.
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).
Astereognosis
MedGen UID:
1848654
Concept ID:
C5848065
Mental or Behavioral Dysfunction
Tactile agnosia refers to the inability to recognize objects by touch, while the inability to discriminate shape and size by touch is also a related condition.
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.
Drooling
MedGen UID:
8484
Concept ID:
C0013132
Finding
Habitual flow of saliva out of the mouth.
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.
Narrow forehead
MedGen UID:
326956
Concept ID:
C1839758
Finding
Width of the forehead or distance between the frontotemporales is more than two standard deviations below the mean (objective); or apparently narrow intertemporal region (subjective).

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVSyndromic X-linked intellectual disability Hedera type
Follow this link to review classifications for Syndromic X-linked intellectual disability Hedera type in Orphanet.

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...