A clinicopathological study and transthyretin (TTR) gene analysis were performed on two families with familial amyloid polyneuropathy (FAP) that had recently been found in Argentina. One family originated in Portugal and the other in France/Spain, Patients suffered from sensorimotor polyneuropathy with autonomic dysfunction, and the TTR gene abnormality (Val 30-->Met) was confirmed in both families. TTR-related FAP is more widely distributed than previously recognized.