Change in the age of onset in patients with familial amyloidotic polyneuropathy type I.

To investigate the influence of environmental factor(s) on the pathogenesis of familial amyloidotic polyneuropathy (FAP) type I, the age of onset in 33 FAP patients in the Arao district of Kumamoto Prefecture in Japan and in 20 of their ancestors to the 3rd prior generation was carefully examined. The age of onset in FAP patients progressively became younger. This tendency was more apparent in female FAP patients than in male patients. Since the pathogenesis of amyloid formation in FAP as well as other amyloidosis diseases is not still elucidated, this phenomenon may be of interest.