Charcot-Marie-Tooth diseases: an update and some new proposals for the classification.

Abstract

Charcot-Marie-Tooth (CMT) disease, the most frequent form of inherited neuropathy, is a genetically heterogeneous group of disorders of the peripheral nervous system, but with a quite homogeneous clinical phenotype (progressive distal muscle weakness and atrophy, foot deformities, distal sensory loss and usually decreased tendon reflexes). Our aim was to review the various CMT subtypes identified at the present time. We have analysed the medical literature and performed a historical retrospective of the main steps from the individualisation of the disease (at the end of the nineteenth century) to the recent knowledge about CMT. To date, >60 genes (expressed in Schwann cells and neurons) have been implicated in CMT and related syndromes. The recent advances in molecular genetic techniques (such as next-generation sequencing) are promising in CMT, but it is still useful to recognise some specific clinical or pathological signs that enable us to validate genetic results. In this review, we discuss the diagnostic approaches and the underlying molecular pathogenesis. We suggest a modification of the current classification and explain why such a change is needed.