The Thr(118)Met substitution in the peripheral myelin protein 22 (PMP22) gene has been detected in a number of families with demyelinating Charcot-Marie-Tooth (CMT1) neuropathy or with the hereditary neuropathy with liability to pressure palsy, but in none of them has it consistently segregated with the peripheral neuropathy.
Although PMP22 point mutations are not common, our findings highlight the importance of sequencing the PMP22 gene in patients with variable CMT phenotypes and also confirm that the PMP22 Thr118Met mutation is associated with a neuropathy albeit with reduced penetrance.