PMP22 and Charcot-Marie-Tooth disease type 1A: CMT is a common heritable peripheral neuropathy exhibiting acute severe neurotoxicity after vincristine administration.4, , -7 CMT1A is an autosomal dominant disease resulting from the duplication of PMP22 gene of chromosome 17p11.2.8 The duplication mutation is classified as CMT1A associated with increased expression of PMP.