Intracellular retention, including cytosolic accumulation of PMP22 has been observed in nerves from symptomatic CMT1A patients (Nishimura et al., 1996; Hanemann et al., 2000) indicating that age-associated changes in subcellular protein homoeostatic mechanisms likely contribute to the pathogenesis of the disease. Here, PMP22 is linked to Charcot-Marie-Tooth disease type 1A.