Four novel mutations of the myelin protein zero gene presenting as a mild and late-onset polyneuropathy.

Inherited neuropathies caused by mutations of the major structural protein of peripheral myelin, myelin protein zero (MPZ), contribute to 5% of all cases of Charcot-Marie-Tooth disease (CMT). They can be divided into an early-onset neuropathy with symptoms prior to the stage of walking, and a late-onset neuropathy with symptoms at the age of 40 and older. In this study, five patients with four novel MPZ mutations were identified by molecular genetic testing which presented as mild and late-onset neuropathies. We recommend testing for MPZ mutations in patients with a late-onset neuropathy, as late-onset inherited neuropathies might be more frequent than previously thought.