Charcot-Marie-Tooth disease type 4B1

What it is

A form of Charcot-Marie-Tooth disease type 4 characterized by an early childhood-onset of severe, demyelinating sensorimotor neuropathy, various degrees of complex myelin outfoldings seen on peripheral nerve biopsy, very slow, and often undetectable, nerve conduction velocities, and the typical CMT phenotype (i.e. distal muscle weakness and atrophy, sensory loss, absence of deep tendon reflexes, and frequent pes cavus). Other reported features include facial weakness, vocal cord paresis, respiratory difficulties, and skeletal deformities (e.g. chest deformities, claw hands, pes equinovarus).

Key facts

Prevalence

<1 / 1 000 000

Age of onset

Infancy, Neonatal

Inheritance

Autosomal recessive

Classified as

Disease

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Gene

ICD-10 codes

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Related health topics

Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.

Cross-references