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Charcot-Marie-Tooth disease type 4G

Synonym(s) CMT4G
Hereditary motor and sensory neuropathy, Russe Type
Prevalence Unknown
Inheritance Autosomal recessive
Age of onset Childhood
  • G60.0
MeSH -
MedDRA -


Disease definition

Charcot-Marie-Tooth disease, type 4G (CMT4G) is a demyelinating CMT peripheral sensorimotor polyneuropathy.


It has been identified in Bulgarian, Romanian, French, and Spanish Gypsies and is also referred to as hereditary motor and sensory neuropathy-Russe (HMSNR).

Clinical description

Onset occurs between 8 and 16 years of age with distal lower limb weakness, followed by distal upper limb involvement with a more variable age of onset of between 10 and 43 years. Sensory loss is also a prominent feature.


The disease-causing gene has not yet been identified but linkage analysis and recombination mapping have led to identification of a small interval on 10q23.2.

Diagnostic methods

Motor nerve conduction velocities are moderately reduced and the threshold for electrical nerve stimulation is increased. Nerve biopsies reveal a loss of large myelinated fibers, reduced thickness of the myelin sheath and profuse regenerative activity.

Genetic counseling

CMT4G is transmitted in an autosomal recessive manner.

Expert reviewer(s)

  • Dr Carmen ESPINÓS
  • Pr Francesc PALAU

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