Genetic polymorphisms in base excision repair in healthy slovenian population and their influence on DNA damage

Genetic polymorphisms in DNA repair genes may result in altered DNA damage. The aim of our study was to determine the frequencies of common functional single nucleotide polymorphisms (SNPs) in specific base-excision DNA repair (BER) genes in healthy Slovenian population and evaluate their influence on DNA damage established by comet assay. In total 141 unrelated healthy subjects were genotyped for hOGG1 Ser326Cys, XRCC1 Arg194Trp and Arg399Gln polymorphisms by real-time TaqMan assay. The frequencies of the hOGG1 326Ser/Ser, 326Ser/Cys and 326Cys/Cys genotypes were 63.8, 29.8, and 6.4%, respectively. The frequency distribution of XRCC1 polymorphism was 88.7% for 194Arg/Arg, 9.2% for 194Arg/Trp, 2.1% for 194Trp/Trp and 46.8% for 399Arg/Arg 40.4% for 399Arg/Gln, 12.8% for 399Gln/Gln. The influence of selected BER polymorphisms on the percentage of comet tail DNA (% TD) was determined in a subgroup of 26 subjects. We found that% TD was significantly increased among individuals with hOGG1 326Ser/Cys heterozygous variant genotype as compared to 326Ser/Ser wild-type genotype (% TD = 8.9 ± 4.2 vs. % TD = 6.9 ± 1.4, P = 0.017). No significant associations between XRCC1 Arg194Trp and Arg399Gln polymorphisms and% TD were found. Our results confirmed that DNA damage is modulated by hOGG1 Ser326Cys polymorphism.