PMP22 and hereditary neuropathy with liability to pressure palsies: Duplication of the human peripheral myelin protein 22 (PMP22)/growth arrest-specific gene 3 (gas-3), is responsible for Charcot–Marie–Tooth type 1 A (CMT1A) neuropathy, while haploinsufficiency is linked with hereditary neuropathy with liability to pressure palsy (HNPP) [1].