FAMILIAL AMYLOIDOTIC POLYNEUROPATHY IN SWEDEN - A PEDIGREE ANALYSIS

Extended genealogical studies were performed on the heredity patterns in Swedish patients with familial amyloidotic polyneuropathy (FAP) usi ng Swedish historical archives. The population studied included 239 pa tients: 109 patients were linked to five large pedigrees and 80 patien ts belonged to 30 smaller pedigrees or nuclear families. In the remain ing 50 cases, no genealogical links were found. Differences in mean ag es of onset between the different pedigrees were found, although a con siderable variation within the pedigrees was also present. There was a tendency for later ages of onset among older generations than younger ones: descendants of affected mothers seem to be more prone to antici pation in age of onset than descendants of affected fathers. Furthermo re, there seems to be a tendency for earlier ages of onset among patie nts with a carrier mother than a carrier father. Some extended pedigre es, from the Skelleftea and Pitea areas, are presented in detail. The former go back into the middle of the 17th century. One important conc lusion is that the mutational event may have occurred in late mediaeva l times.