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Charcot-Marie-Tooth disease type 4K(CMT4K)

MedGen UID:
895560
Concept ID:
C4225246
Disease or Syndrome
Synonyms: CHARCOT-MARIE-TOOTH DISEASE, DEMYELINATING, AUTOSOMAL RECESSIVE, TYPE 4K; CHARCOT-MARIE-TOOTH DISEASE, DEMYELINATING, TYPE 4K; CHARCOT-MARIE-TOOTH NEUROPATHY, DEMYELINATING, AUTOSOMAL RECESSIVE, TYPE 4K
SNOMED CT: Charcot-Marie-Tooth disease type 4K (765047006); SURF1-related Charcot-Marie-Tooth disease type 4 (765047006); SURF1-related severe demyelinating Charcot-Marie-Tooth disease (765047006); SURF1, cytochrome c oxidase assembly factor related Charcot-Marie-Tooth disease type 4 (765047006)
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
141025
Concept ID:
C0441748
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele).
 
Gene (location): SURF1 (9q34.2)
 
Monarch Initiative: MONDO:0014733
OMIM®: 616684
Orphanet: ORPHA391351

Definition

Charcot-Marie-Tooth disease type 4K (CMT4K) is an autosomal recessive demyelinating peripheral neuropathy characterized by onset in the first decade of distal muscle weakness and atrophy associated with impaired distal sensation. Both upper and lower limbs are affected. Affected individuals may also have nystagmus and late-onset cerebellar ataxia. Laboratory studies show increased serum lactate and isolated mitochondrial complex IV deficiency (summary by Echaniz-Laguna et al., 2013). For a phenotypic description and a discussion of genetic heterogeneity of autosomal recessive demyelinating Charcot-Marie-Tooth disease, see CMT4A (214400). [from OMIM]

Clinical features

From HPO
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.
Hearing impairment
MedGen UID:
235586
Concept ID:
C1384666
Disease or Syndrome
A decreased magnitude of the sensory perception of sound.
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.
Peripheral neuropathy
MedGen UID:
18386
Concept ID:
C0031117
Disease or Syndrome
Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course.
Areflexia
MedGen UID:
115943
Concept ID:
C0234146
Finding
Absence of neurologic reflexes such as the knee-jerk reaction.
Gait disturbance
MedGen UID:
107895
Concept ID:
C0575081
Finding
The term gait disturbance can refer to any disruption of the ability to walk.
Peripheral demyelination
MedGen UID:
451074
Concept ID:
C0878575
Pathologic Function
A loss of myelin from the internode regions along myelinated nerve fibers of the peripheral nervous system.
Axonal loss
MedGen UID:
316962
Concept ID:
C1832338
Finding
A reduction in the number of axons in the peripheral nervous system.
Easy fatigability
MedGen UID:
373253
Concept ID:
C1837098
Finding
Increased susceptibility to fatigue.
Muscular atrophy
MedGen UID:
892680
Concept ID:
C0541794
Pathologic Function
The presence of skeletal muscular atrophy (which is also known as amyotrophy).
Kyphoscoliosis
MedGen UID:
154361
Concept ID:
C0575158
Anatomical Abnormality
An abnormal curvature of the spine in both a coronal (lateral) and sagittal (back-to-front) plane.
Increased circulating lactate concentration
MedGen UID:
332209
Concept ID:
C1836440
Finding
Abnormally increased level of blood lactate (2-hydroxypropanoic acid). Lactate is produced from pyruvate by lactate dehydrogenase during normal metabolism. The terms lactate and lactic acid are often used interchangeably but lactate (the component measured in blood) is strictly a weak base whereas lactic acid is the corresponding acid. Lactic acidosis is often used clinically to describe elevated lactate but should be reserved for cases where there is a corresponding acidosis (pH below 7.35).
Horizontal nystagmus
MedGen UID:
124399
Concept ID:
C0271385
Disease or Syndrome
Nystagmus consisting of horizontal to-and-fro eye movements.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVCharcot-Marie-Tooth disease type 4K

Recent clinical studies

Clinical prediction guides

Rubino A, Bruno G, Mazio F, de Leva MF, Ruggiero L, Santorelli FM, Varone A
Neuropediatrics 2022 Jun;53(3):208-212. Epub 2021 Dec 1 doi: 10.1055/s-0041-1739135. PMID: 34852375