Abstract: Objective To explore the 5,10-methylenetetrahydrofolate reductase (MTHFR) and 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) gene polymorphisms among the Han women in Zhangjiagang city. Method A total of 4008 Han women were recruited. And their oral epithelial cells were collected to extract genome DNA in order to detect gene polymorphisms of MTHFR and MTRR using fluorescence quantitative PCR. Then the results were compared with those in other cities in China. Results The genotype frequencies of MTHFR C677T CC, CT and TT among Zhangjiagang women are 32.2%, 49.5% and 18.3% 18.3%, respectively. The C allele frequency is 64.3%, T allele frequency is 35.7%. The genotype frequencies of MTHFR A1298C AA、AC and CC are 68.7%、28.7% and 2.5%, respectively. The A allele frequency is 80.8%, C allele frequency is 19.2%. The genotype frequencies of MTRR A66G AA, AG and GG are 54.4%、38.5% and 7.1%, respectively. The A allele frequency is 76.3%, G allele frequency is 26.4%. Conclusion The MTHFR, MTRR polymorphism distribution of Han women in Zhangjiagang city is region specific.

Key words: Methylenetetrahydrofolate reductase, Methionine synthase reductase, Single nucleotide