Hearing loss as the first feature of late-onset axonal CMT disease due to a novel P0 mutation.

A Czech family with three individuals carrying a novel mutation, 290 A-->T (Glu97Val), in the myelin protein zero gene (P0) is reported. The two eldest carriers developed progressive sensorineural hearing loss and abnormal pupillary reaction at age 18. These preceded the onset of the classic signs of Charcot-Marie-Tooth disease (CMT) by more than a decade. Sural nerve biopsy and nerve conduction studies were compatible with the axonal type of CMT. The authors show that progressive hearing loss can be the first symptom in P0 mutation carriers.