Recurrent syncope as persistently isolated feature of transthyretin amyloidotic polyneuropathy.

In transthyretin familial amyloid polyneuropathy (TTR-FAP), single clinical features rarely remain isolated and are usually accompanied by other symptoms. We describe a patient with TTR-FAP, who had recurrent episodes of syncope for 4 years as an overt and isolated symptom. Later, he experienced paresthesia in the hands, and impotence. Molecular analysis of the TTR gene revealed a Thr49Ala mutation. The unusual clinical presentation presents a diagnostic challenge.