PMP22 (peripheral myelin protein-22) is an integral membrane glycoprotein of internodal myelin and comprises an estimated 2-5 % of total myelin protein contents of peripheral nervous system. Its functional importance is emphasized by the fact that PMP22 gene mutations are the most common causes for inherited peripheral nerve disorders, also known as CMT (Charcot-Marie-Tooth diseases). Mutations of PMP22 are responsible for more than half of all the patients with inherited peripheral neuropathies, including CMT1A/CMT- type-1A with trisomy of PMP22, hereditary neuropathy with liability to pressure palsies (HNPP) with heterozygous deletion of PMP22, and CMT1E with point mutations of PMP22. These PMP22 associated disorders disrupt the organization of myelin, and subsequently axonal integrity which is untimately responsible for disabilities in patients. While overexpression and point-mutations of the PMP22 gene produces gain-of-function phenotypes, PMP22 deletion results in a loss-of-function phenotype that reveals the normal physiological functions of the PMP22 protein.