New vistas on the pathomechanism of Charcot-Marie-Tooth and related peripheral neuropathies.

A gene-dosage mechanism in CMT1A and HNPP has been postulated previously. Here, recent findings are discussed concerning (i) the functional consequences of altered PMP22 expression on Schwann cell growth regulation and on the capacity of genetically modified Schwann cells to myelinate peripheral axons, (ii) the cell physiological effects caused by the expression of certain disease-related missense mutations of PMP22 that are known to alter the Schwann cell phenotype and impair myelination in vivo, and (iii) the pathomechanism of CMT1 in light of findings on a novel association between PMP22 and P0 in PNS myelin.