Clinical and pathological findings of non-Val30Met TTR type familial amyloid polyneuropathy in Japan.

Non-Val30Met TTR type FAP is being increasingly recognized; a total of 21 TTR gene mutations related to the development of non-Val30Met type FAP have been identified among Japanese. The clinical phenotypes of these FAP kindreds varied considerably corresponding to the different mutations of TTR gene. In the nervous system, peripheral nerve involvement sometimes started as a carpal tunnel syndrome in addition to peripheral somatic and autonomic neuropathy. Brain and spinal cord dysfunctions due to leptomeningeal amyloidosis infrequently appeared. Severe involvement of the heart was a common finding in the visceral organs, which might causally lead to a poor prognosis for the patients with this form of FAP. Several patients with ATTR non-Val30Met have recently undergone living-related partial liver transplantation, and their postoperative courses have been under careful investigation.