Clinical variability in type I familial amyloid polyneuropathy (Val30Met): comparison between late- and early-onset cases in Portugal.

We compared early- with late-onset cases in 86 patients with familial amyloidotic polyneuropathy type I (FAP). Among these patients, 43 presented before age 50 (early-onset) and 43 after this age (late-onset). Sex and geographical distribution were similar, although a family history of the disorder was more frequent in early-onset cases. In late-onset disease, autonomic dysfunction was less frequent, but organ involvement and severe neuropathic pain were more frequent. Neurophysiological measurements were similar. FAP is a cause of neuropathy in elderly patients, in particular in those presenting with neuropathic pain.