亚甲基四氢叶酸还原酶基因C677T突变与冠心病的连锁分析

目的探讨亚甲基四氢叶酸还原酶(methylenetetrahydrofolatereductase, MTHFR)基因C677T突变是否与冠心病连锁。方法应用传递不平衡检验(transmission/disequilibriumtest, TDT)分析了先证者一级亲属中至少有1例冠心病患者的冠心病家系45个，调查了212人。其中完整核心家系、父母一方、双方基因型缺失家系分别为21、2和22个。PCR-RFLP鉴定MTHFR基因C677T位点基因型。结果23个核心家系经经典TDT分析，杂合子父母传递给患病子女的T等位基因频率未显著偏离50%(P＞0.05)；对40个符号要求的同胞组资料的同胞传递不平衡检验(sibtransmission/desequilibrium test, STDT)和同胞组不平衡检验(sibship disequilibruiumtest, SDT)检验均未发现受累子代与非受累子代T等位基因分布差异有显著性(P＞0.05)。结论MTHFR基因C677T突变与冠心病不连锁，提示该位点可能不是中国人冠心病的遗传易患因子之一。

Study on the relationship between methylenetetrahydrofolate reductase gene C677T mutation and coronary heart disease

OBJECTIVE: To investigate whether methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism is linked with coronary heart disease (CHD). METHODS: Transmission/disequilibrium test(TDT), sib transmission/disequilibrium test(STDT), and sibship disequilibrium test(SDT) were used. Forty-five CHD pedigrees with at least one CHD patient in the first degree relatives of probands were recruited from Oct. 1998 to Feb. 1999. Among those recruited were 21, 2 and 22 pedigrees with the genotypes of both parents known, one parental genotype unknown and both unknown, respectively. MTHFR genotype was measured by PCR-RFLP technique. RESULTS: Neither the TDT for 23 nuclear families with at least one parental genotype known or the STDT and SDT for 40 sibships found significant difference between the transmitted and untransmitted MTHFR gene 677T allele distributions. CONCLUSION: The above results suggest that MTHFR gene 677T allele is probably not linked with CHD in Chinese population.