Polymorphism of the regulatory region of the presenilin-2 gene in sporadic Alzheimer's disease: A case-control study

presenilin-2 is one of the causative genes for familial Alzheimer's disease, and the apolipoprotein E ε4 allele is a major genetic risk factor for late-onset and sporadic early-onset Alzheimer's disease. Polymorphism of the regulatory region of presenilin-2 has recently been reported to be associated with sporadic Alzheimer's disease in a Russian population. The purpose of this study was to determine whether Alzheimer's disease is associated with the presenilin-2 gene polymorphism and the apolipoprotein E genotype in an extended case-control study. We examined 230 patients with Alzheimer's disease, along with an equal number of age- and sex-matched controls from the same community, in a Japanese population by using a Chi-square test for homogeneity and a logistic regression analysis. The presenilin-2 polymorphism frequencies were similar in early-onset Alzheimer's disease patients (0.17) and younger controls (0.15), and in late-onset Alzheimer's disease (0.20) and elderly controls (0.20). We found no evidence for an association between the presenilin-2 polymorphism and the apolipoprotein E ε4 allele. Our results fail to support an association of presenilin-2 gene polymorphism with Alzheimer's disease. The discrepancy between our results and the results of the Russian study appear to be due to racial differences.