FAMILIAL AMYLOID polyneuropathy type I (transthyretin Met30–associated familial amyloid polyneuropathy; FAP TTR Met30), in which methionine is substituted for valine at position 30 of transthyretin, is the most common type of familial amyloid polyneuropathy in Japan, as well as in Western countries.
1-13 Typically, FAP TTR Met30 has been characterized by onset in the second or third decade of life, a high penetrance rate, marked autonomic dysfunction, loss of superficial sensation including nociception and thermal sensation, and steady progression of disease over 10 to 15 years.
2,7,13,14 In Japan, these patients are concentrated in 2 geographic areas: the village of Ogawa in Nagano prefecture on the island of Honshu and the city of Arao in Kumamoto prefecture on the island of Kyushu.
2,6,7,10