The prevalence of the E2 allele has been found to be significantly lower in individuals with dementia.148 E2 allele was suggested to be protective against AD.145 Further, APOE E2 and E3 may participate in neuronal maintenance and repair.145 A Korean study detected significant correlation between the APOE E4 allele and AD.149 Genotyping analysis was performed in a group of AD patients and healthy individuals (controls). The allele and genotype frequency were compared using chi-square and Fisher’s exact tests. The frequency of the APOE E4 allele in the EOAD and LOAD groups was significantly higher than in the control group. However, the study failed to find any difference in the E2 allele between AD patients and controls. These findings suggest that the E2 allele might not play a protective role against AD in Korea.149
