Simultaneous analysis of five genetic risk factors in Polish patients with Alzheimer's disease

As Alzheimer's disease (AD) is a complex disease, we decided to estimate how previously reported genetic polymorphisms interact to increase the risk for the disease. Five candidate genes were chosen: apolipoprotein E (APOE), alpha 2-macroglobulin, cathepsin D, myeloperoxidase and nitric oxide synthase. Genotyping was performed in 100 cases of late-onset AD and 100 healthy controls. We found a highly significant difference in APOE epsilon 4 distribution between groups (P<0.005). However, no evidence of association for other studied loci was found. Cumulative analysis of five genetic polymorphisms was performed, but it also failed to reveal any synergistic effect of candidate genes greater than that caused by APOE itself. Our results suggest that the APOE epsilon 4 allele is the only known genetic risk factor for late-onset, sporadic AD.