The -491 TT apolipoprotein E promoter polymorphism is associated with reduced risk for sporadic Alzheimer's disease

Homozygosity for the A allele of the -491 A/T apolipoprotein E (APOE) promo ter polymorphism has recently been reported to be associated with sporadic Alzheimer's disease (AD). Two hundred and fifty one patients with AD and an equal number of controls derived from the same region in a Spanish populat ion, were genotyped for -491 A/T and epsilon2/ epsilon3/epsilon4 APOE polym orphisms. We did not detect an elevated -491 AA genotype frequency when com paring AD cases to controls. In contrast, persons homozygous for the T alle le were at a significantly reduced risk of AD (odds ratio of 0.10, P = 0.00 6). Multiple logistic regression analysis indicated that the -491 TT polymo rphism added information on the risk of AD which was independent of that of the APOE epsilon4 allele. (C) 2001 Elsevier Science Ireland Ltd. All right s reserved.