Clinical variant of familial amyloid polyneuropathy.

Hereditary amyloidosis with early and prominent peripheral nerve involvement is often designated familial amyloid polyneuropathy (FAP). The abnormality usually lies in the transthyretin (TTR) gene. We describe a patient with a tyr77 TTR gene mutation who presented with sensorimotor polyneuropathy but no other systemic symptoms of amyloidosis. This is one of a few documented cases of the tyr77 mutation in North America. The clinical and electrophysiologic features of this unusual cause of sensorimotor polyneuropathy are discussed.