FAMILIAL RISKS FOR ALZHEIMER-DISEASE FROM A POPULATION-BASED SERIES

Kaplan-Meier risks estimates are calculated and compared for two conse cutive series (N-1 = 840, N-2 = 819) of first-degree relatives of Alzh eimer disease (AD) patients diagnosed as either ''probable'' or ''auto psy-confirmed'' AD. The consistency of results increases confidence in estimates and suggests consistent case ascertainment over 8 years. Li fetime risk estimates to age 88 for the combined sample (23.4% +/- 3.0 %) do not approach the 50% risk compatible with an autosomal dominant model of transmission. These results support our previous finding and suggest that an autosomal dominant gene(s) is not responsible for all cases of AD. (C) 1994 Wiley-Liss,Inc.