Over the last 15 years, a number of genetic loci and genes for Charcot-Marie-Tooth(CMT)disease have been identified.CMT patients can be categorized into two types, demyelinationand axonal loss.Charcot-Marie-Tooth type 4F neuropathy(CMT4F) is an autosomalrecessive demyelinating caused by mutations in the periaxin gene(PRX) mapped on 19q13.So far, 18 different frameshift or non-sense PRX mutations were found to cause autosomalrecessive early-onset demyelinating neuropathy, which develop in the severe demyelinatingwith slow or no progression.