Charcot-Marie-Tooth (CMT) disease: an update

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Charcot-Marie-Tooth (CMT) disease: an update]

Vallat JM, Funalot B.

Service de neurologie, Laboratoire de neuropathologie, neuropathies

périphériques rares, Centre de référence, Laboratoire de biochimie et génétique

moléculaire, CHU de Limoges, Limoges Cedex, France.

Abstract

Charcot-Marie-Tooth (CMT) <<disease>> is the generic name given to a group of

genetic disorders characterized by a relatively isolated dysfunction of

peripheral nerves, with combined motor and sensory impairment.

These CMT syndromes are the most frequent genetically-determined peripheral

neuropathies, with a global prevalence between 4.7 and 36/100,000.

Their clinical phenotype is predominantly motor, with a grossly symmetrical

distal amyotrophy involving both lower and upper limbs. Mode of inheritance is

variable: autosomal dominant, autosomal recessive or X-linked.

Apparently sporadic forms can be a difficult diagnosis and they must be

considered in all patients with a chronic polyneuropathy which is not clearly of

acquired origin.

During the last two decades, the identification of more than 25 genes mutated in

CMT syndromes has complicated the classification of these disorders. Knowledge

of the function of some of these genes has improved our understanding of the

pathogenesis of myelinic or axonal dysfunction in CMT, but for some others their

function remains elusive or unknown.