Congenital hypo- and hypermyelination neuropathy. Two cases.

Two young patients were referred recently to the authors for investigation of a peroneal atrophy syndrome. Since the first symptoms were observed in infancy, a congenital hypomyelination neuropathy was suspected, and superficial peroneal nerve biopsies were taken. Signs of severe and widespread demyelination/remyelination were observed. These features appeared morphologically similar to those observed in the globular or tomaculous neuropathies. The mechanism of the hypermyelination is discussed.