PMP22 and Charcot-Marie-Tooth disease type 1A: Presumably, PMP22 duplications eventually lead to overexpression of PMP22 protein, which causes the CMT1A phenotype.[24] However, the pathogenesis of PMP22 duplications related CMT1A seems not same as that in CMT patients with PMP22 small mutations.[25] Moreover, it was also recognized that PMP22 is important to both the sealing of myelinated nerve fibers and their protection from mechanical stresses, and PMP22 point mutation in Trembler-J mice exhibits impaired mechanical integrity.[26]