Distribution of the rs3136794 Polymorphism of the DNA Polymerase β Involved in the Base Excision Repair Pathway, in World-Wide Population

Abstract

Genes in the base excision repair (BER) pathway influence the generation and repair of oxidative lesions. The mammalian short-patch BER is primarily attributed to the human 8-oxoguanine DNA glycosylase (hOGG1), apurinic/apyrimidinic endonuclease 1 (APE1), DNA polymerase β (pol β), and X-ray repair cross-complementing group 1 (XRCC1) pathways. There have been many reports of differences among individuals and populations regarding polymorphisms of hOGG1, APE1, and XRCC1 genes and metabolism. However, there are only a limited number of reports available concerning pol β polymorphisms. Therefore, the aim of the present study was to evaluate the frequencies of a common single nucleotide polymorphism (SNP) of the polymerase β rs3136794 gene in the worldwide population. Our sample consisted of 1,540 healthy individuals from Japan, Korea, Tibet, Nepal, Sri Lanka, Vietnam, Mexico, Namibia, Ghana, and South Africa. We observed that the A allele was the most common allele in Asia and Mexico, ranging from 58.5 to 94.7 %, respectively. On the other hand, the G allele was the most common allele in Africa, ranging from 23.4 to 25.3 %. In conclusion, the distribution of the rs3136794 gene polymorphism distinguishes the African population studied from other populations; however, it is necessary to increase the size of the samples to acquire more conclusive results. This study is the first to demonstrate the existence of genetic heterogeneity in a worldwide distribution of SNPs in a pol β gene (rs3136794) in the BER genes.