Charcot-Marie-Tooth disease axonal type 2Q(CMT2Q)

MedGen UID:: 767280
•Concept ID:: C3554366
•: Disease or Syndrome

Synonyms:	CHARCOT-MARIE-TOOTH DISEASE, AXONAL, AUTOSOMAL DOMINANT, TYPE 2Q; CHARCOT-MARIE-TOOTH NEUROPATHY, TYPE 2Q
SNOMED CT:	Autosomal dominant Charcot-Marie-Tooth disease type 2Q (773393001)
Modes of inheritance:	Autosomal dominant inheritance MedGen UID: 141047 •Concept ID: C0443147 • 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 heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Autosomal dominant inheritance (Orphanet)

Gene (location): Gene(s) directly associated with this condition or phenotype.	DHTKD1 (10p14)

Monarch Initiative:	MONDO:0014012
OMIM®:	615025
Orphanet:	ORPHA329258

Definition

A rare subtype of autosomal dominant Charcot-Marie-Tooth disease type 2 with characteristics of adolescent to adulthood-onset of symmetrical, slowly progressive distal muscle weakness and atrophy (with a predominant weakness of the distal lower limbs) associated with reduced or absent deep tendon reflexes, pes cavus and mild to moderated deep sensory impairment. There is evidence this disease is caused by a heterozygous loss-of-function mutation in the DHTKD1 gene on chromosome 10p14. [from SNOMEDCT_US]

Clinical features

From HPO

Pes cavus

MedGen UID:: 675590
•Concept ID:: C0728829
•: Congenital Abnormality

An increase in height of the medial longitudinal arch of the foot that does not flatten on weight bearing (i.e., a distinctly hollow form of the sole of the foot when it is bearing weight).

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Distal lower limb muscle weakness

MedGen UID:: 324514
•Concept ID:: C1836450
•: Finding

Reduced strength of the distal musculature of the legs.

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Hyporeflexia

MedGen UID:: 195967
•Concept ID:: C0700078
•: Finding

Reduction of neurologic reflexes such as the knee-jerk reaction.

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Impaired distal vibration sensation

MedGen UID:: 381262
•Concept ID:: C1853767
•: Finding

A decrease in the ability to perceive vibration in the distal portions of the limbs.

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Somatic sensory dysfunction

MedGen UID:: 1790456
•Concept ID:: C5551413
•: Finding

An abnormality of the primary sensation that is mediated by peripheral nerves (pain, temperature, touch, vibration, joint position). The word hypoesthesia (or hypesthesia) refers to a reduction in cutaneous sensation to a specific type of testing.

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Difficulty walking