Association study of susceptibility genes for late-onset Alzheimer's disease in the Japanese population

APOE is an established susceptibility gene for late-onset Alzheimer's disease (LOAD). Recent genome-wide association studies have identified many additional susceptibility genes for LOAD in populations of European descent. However, there is little information on whether or not genetic variants in these genes are associated with other ethnicities. To investigate the association of seven genes identified by genome-wide association studies, we carried out a case-control study using 825 LOAD cases and 2934 controls in the Japanese population. For the APOE gene, APOE-ε4 carriers had a 4.54-fold higher risk than APOE-ε4 noncarriers after adjusting for age and sex (P=4.6×10^-27). For other genes, the single-nucleotide polymorphism in the PICALM gene was significantly associated with LOAD (P=0.02, odds ratio=1.23). There was no significant interaction between PICALM and APOE-ε4 carrier status (P for interaction=0.68). Our data indicate that PICALM is also a susceptibility gene for LOAD in the Japanese population.