Hereditary neuropathies.

PURPOSE OF REVIEW: This review will update recent advances in the genetics, clinico-electrophysiological, pathological data and pathophysiology of Charcot-Marie-Tooth disease and related disorders. RECENT
FINDINGS: Hereditary neuropathies continue to be in a state of constant flux, reflecting the rapid advances in the description of causative genes, three additional Charcot-Marie-Tooth genes having been identified in recent months. Such an ever-increasing body of genetic data provides valuable clues to the pathogenetic mechanisms of both nerve demyelination and nerve axonal degeneration. The classification of Charcot-Marie-Tooth disease is increasingly more complex as there are approximately 26 loci; for clinicians to reach a simplified classification is a pressing need. Genotypic-phenotypic correlations are still incomplete and will require further research, starting from both refined molecular investigations and detailed clinical, electrophysiological, and pathological studies. Recent epidemiological surveys have corroborated the fact that Charcot-Marie-Tooth disease is the most common type of hereditary neuropathy.
SUMMARY: Advances in molecular genetics in hereditary neuropathies, and mainly in Charcot-Marie-Tooth disease, have enriched our knowledge of this heterogeneous group of disorders. In spite of this there remain important and basic issues, such as an updated and revised classification of Charcot-Marie-Tooth disorders, the better delineation of phenotypic-genotypic correlations, and further research to map as yet non-localized loci or to identify unknown gene mutations.