Clinical picture and outcome of transthyretin-related familial amyloid polyneuropathy (FAP) in Japanese patients.

Familial amyloid polyneuropathy (FAP) was once considered to be a disease peculiar to endemic areas, but it is now recognized that FAP kindreds exist in worldwide places. The amyloid precursor of FAP is a variant form of transthyretin (TTR) with one amino acid substitution, which is ascribed to a mutation of TTR gene. Corresponding to the variety of the clinical phenotypes of FAP, more than 80 mutations have been identified as causative gene abnormality in this disease. Since the vast majority of TTR in serum is produced in the liver, liver transplantation has become widely accepted as a valuable treatment for FAP.