Apoe epsilon4 allele frequency in patients with dementia in different ethnic and geographic groups

The APOE e4 allele polymorphism is associated with the increased risk of behavioral and psychological signs and symptoms of dementia. Treatment strategies based on APOE genotypes are being developed. In this study, we aimed to assess the frequencies of APOE4 alleles in patients with Alzheimer’s disease (AD) and vascular dementia (VaD) in different ethnic and geographic groups, and compare them with our results. Method: We determined APOE polymorphisms in patients with VaD, AD, and in controls. For comparison, the literature was searched systematically. Out of 80 papers, 42 papers were assessed for APOE genotype and allele frequencies from several regions of America, Asia and Europe. Results: There were marked variations in the APOE allele and genotype frequencies in all groups. The strength of association between AD and APOE e4 allele carrying was found significant [OR:2.905 (95%CI: 1.237-6.823)]. APOE e4 allele frequencies (%) showed gradual increase from controls to the AD patients (Control: nstudies=42; 11.33+5.95; VaD: n=7; 15+5.7; AD: n=21; 28.5+8.83). Conclusion: Although there are more risk factors which accelerate the onset of AD or VaD, these results of comparison confirmed that having APOE e4 allele was one of risk factors for accelerating the onset of AD. The regional determination of frequencies can be invaluable tool for planning the healthcare policy, and also disease management at the individual basis.