Association of <Emphasis Type="Italic">hOGG1</Emphasis> genotype with life style and oxidative DNA damage among Chinese ethnic populations

To assess the natural variation of hOGG1 gene and the gene–environmental interactions, the hOGG1 codon 326 polymorphism and urinary 8-OHdG levels were investigated in large samples (n = 953) of healthy individuals from five Chinese ethnic populations by using PCR-RFLP and HPLC-ECD. Life-style parameters under study were obtained through a questionnaire. The allelic frequencies of the hOGG1 gene in the Chinese populations were found to be 0.16 (Ser/Ser), 0.49 (Ser/Cys) and 0.35 (Cys/Cys), respectively. The frequencies of Ser326Cys polymorphism were significantly different among the five Chinese ethnic populations (P = 0.002). No association was found between the hOGG1 gene polymorphism and other life-style parameters except for the association between Ser326Cys and smoking (P = 0.027). A significant increase of urinary 8-OHdG level was observed in Cys326Cys allelic healthy subjects (P = 0.033). These results suggest that there are natural variations of hOGG1 gene among Chinese ethnic populations. Smoking relates to Cys/Cys polymorphism frequencies, and oxidative DNA damage is repaired less in individuals with the hOGG1 Cys326Cys genotype.