Waardenburg syndrome: a variant with neurological involvement.

A case of a variant of Waardenburg syndrome is reported. A 13-year-old boy with features of Waardenburg syndrome consisting of facial anomalies, heterochromia of the iris and fundus, and congenital sensorineural deafness had a marked mental and motor retardation and developed severe gait disturbance associated with neurological abnormalities including dystonia, muscular stiffness and peripheral neuropathy. Sural nerve biopsy revealed 'onion bulb' formation.