P3‐085: Effects of the Apoe Gene on Cognitive Status and Hippocampus Atrophy Using Data from the Global Alzheimer's Association Interactive Network

Abstract

Background: The polymorphic alleles of apolipoprotein E (APOE) are the main determining factors in the Alzheimer's disease (AD) risk. Among the APOE alleles, E4 allele carriers are at the highest risk for Alzheimer's disease compared to E3 and E2 allele carriers. Even though the risk between Alzheimer's disease and E4 allele are high, some differences in their association were found among different ethnic groups. Moreover, previous studies have reported that the presence of E4 is associated with increased risk for both early onset AD and late onset AD (LOAD). The purpose of our study is to elucidate the direct implications of E4 in the LOAD among Korean population. Methods: The study consisted of 723 normal subjects and 650 AD patients from the Korean population. The two groups were further divided as 258 male and 465 female in the control group and 239 male and 411 female in the AD group respectively. The individuals aged above 65 were included to check the association with LOAD. Blood samples collected from those groups were SNP genotyped. Results: Comparison between the individuals with APOE genotypes have showed the risk of AD and the risk association was dramatically increased for the people with E4/E4 (OR ¼ 64.73), E3/E4 (OR ¼ 2.77), E2/E4 (OR ¼ 2.31), E2/E2 (OR ¼ 1.54), E2/E3 (OR ¼ 1.00) with reference to the commonly found E3/E3 allele (OR ¼ 1.00). In addition, the incidence ratio of AD for E4 carriers were found relatively high compared to the other APOE alleles. Conclusions: The results revealed that E4 carriers are at the highest risk for AD among Korean population and resembling the strong association of E4 with LOAD. In a previous study, the increased risk of E4/E4 was also observed among Japanese (OR ¼ 33.1), Caucasian (OR ¼ 12.5) and African-American (OR ¼ 5.7). Similarly, in this study, the E4/E4 allele exhibited the increased risk for AD. Moreover, the incidence ratio of AD for E4 carriers were also significantly high in both male and female population compared to the other APOE allele carriers.