Recent advances in the molecular pathology of familial amyloid polyneuropathy.

The familial amyloid polyneuropathies (FAP) represent a heterogeneous spectrum of clinical syndromes differing regarding age of onset, rate of progression, and distribution of organ involvement and affecting people from different ethnic groups. Several mutant forms of transthyretin (TTR, formerly referred to as prealbumin) have been identified both in circulating plasma and in amyloid deposits from FAP patients. It is possible that a common factor in the amyloidogenesis process exists among the different forms which might be related to a change produced by the mutation in the three-dimensional structure of TTR. Other genetic or acquired factors affecting tissue composition might also play a role in pathogenesis. The intervening factors in amyloidogenesis in FAP, other than the presence of mutant TTR, are largely unknown and deserve future study.