目的探讨5,10-亚甲基四氢叶酸还原酶及甲硫氨酸合酶还原酶基因多态性与先天性心脏病(congenital heart disease,CHD)之间的关系。方法收集173个先心病核心家庭及97个健康对照核心家庭,盐析法提取基因组DNA,用PCR-RFLP方法确定MTHFR、MTRR基因型。结果按先心病发病类型分组后,与对照组相比,动脉导管未闭、房间隔缺损病人MTHFR 677TT基因型频率(分别是42.9%和54.5%)显著高于对照(23.3%),OR值为2.47、3.95;动脉导管未闭病人的母亲与对照组母亲相比,TT基因型频率显著高于对照组母亲,分别为24.5%,42.9%,OR值为2.31。对得到的先心病核心家庭进行传递失衡检验、基于单体型的单体型相对危险度(HHRR)进行统计,发现MTHFR677基因多态性不存在遗传失衡现象。对102个核心家庭的MTRR66位基因多态性分析,不存在遗传失衡现象。结论MTHFR 677TT基因型是CHD尤其是动脉导管未闭、房间隔缺损发生的危险因素之一;母亲TT基因型是子代发生动脉导管未闭的危险因素之一。 Objective To investigate the relationship between 5,10-methylenetetrahydrofolate reductase and methionine synthase reductase gene polymorphism and congenital heart disease (CHD). Methods A total of 173 core families of core congenital heart disease and 97 healthy controls were collected. The genomic DNA was extracted by salting out and the MTHFR and MTRR genotypes were determined by PCR-RFLP. Results According to the incidence of congenital heart disease, the frequency of MTHFR 677TT genotype (42.9% and 54.5%, respectively) was significantly higher in patients with patent ductus arteriosus and atrial septal defect compared with the control group (23.3%), OR was 2.47, 3.95. The frequency of TT genotype was significantly higher in mothers with patent ductus arteriosus than those in control group (24.5%, 42.9%, OR = 2.31, respectively). Transmission disequilibrium test was performed on the obtained core family of CHD patients. Based on haplotype haplotype relative risk (HHRR) statistics, it was found that there was no genetic imbalance in the MTHFR677 gene polymorphism. There was no genetic imbalance in the MTRR66 polymorphism analysis of 102 core families. Conclusions MTHFR 677TT genotype is one of the risk factors of CHD, especially patent ductus arteriosus and atrial septal defect. TT genotype of mother is one of the risk factors of patent ductus arteriosus in offspring.