ANALYSIS OF THE APOE ALLELES IMPACT IN DOWNS-SYNDROME

Down's syndrome (DS) patients develop the characteristic features of A lzheimer's disease (AD) by their fourth decade, some of them exhibitin g an AD-type dementia. We studied the apolipoprotein E (APOE) allele d istribution in a population of 41 DS patients comprising 19.5% of deme nted, compared to 35 control subjects. No statistical difference was o bserved, but the epsilon 2 allele may delay the age of dementia. As de scribed in other studies, the impact of the different APOE alleles in DS is modest. However the compilation of all published studies on AD-t ype dementia in DS suggests that the epsilon 2 allele has a protective effect. In delaying the age of onset, the epsilon 2 allele would have a similar action in AD-type dementia in DS and in AD families with am yloid precursor protein (APP) mutations. Copyright (C) 1996 Elsevier S cience Ireland Ltd.