Objective: To assess the natural variation of hOGG1 gene and the gene-environmental interactions.
Methods: The hOGG1 codon 326 polymorphism and urinary 8-OHdG levels were investigated in a large sample of healthy individuals (n = 953) from five ethnic populations in China by using PCR-RFLP and HPLC-ECD. Life style parameters were obtained through a questionnaire survey.
Results: The allelic frequencies of hOGG1 gene in whole subjects were 0.16 (Ser/Ser), 0.49 (Ser/Cys) and 0.35 (Cys/Cys). The frequency of Ser326Cys was significantly different among the five 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).
Conclusion: There are natural variations of hOGG1 gene in different ethnic populations in China. Smoking is related to the frequencies of Cys/Cys polymorphism, and the repairing of oxidative DNA damage is lower in individuals with the hOGG1 Cys326Cys genotype.