MPZ and Charcot-Marie-Tooth disease: Mutations in the myelin protein zero (MPZ) gene are a major cause of inherited neuropathy and can manifest in a wide range of clinical phenotypes, ranging from early-onset forms, as Dejerine–Sottas syndrome (DSS) and congenital hypomyelination (CH), to less severe, adult onset, Charcot–Marie–Tooth diseases (CMT) [18,23].