FAMILIAL AMYLOIDOTIC POLYNEUROPATHY IN SWEDEN - GEOGRAPHICAL-DISTRIBUTION, AGE-OF-ONSET, AND PREVALENCE

Familial amyloidotic polyneuropathy (FAP) in Swedish patients is assoc iated with the same transthyretin mutation (TTR(Met30)) as in Portugue se, Japanese, Brazilian and Majorcan patients. Yet, the age of onset o f FAP is much later in Sweden than in other populations. We have studi ed 239 cases of FAP from northern Sweden, their geographical distribut ion, differences in age of onset, and estimated prevalence and inciden ce rates. Cases and families concentrate mainly in two areas, around t he towns of Skelleftea and Pitea. Mean age of onset was found to be la ter in the Pitea (58.8 +/- 10.8) than in the Skelleftea area (54.4 +/- 13.5). Unusually high figures were found for prevalence rates (91 x 1 0(-5) and 104 x 10(-5), respectively) in 1985. Mean yearly incidences were 3.1 x 10(-5) and 4.4 x 10(-5), respectively, over the period 1985 -1989.