同型半胱氨酸代谢酶基因多态性与深静脉血栓的相关性研究

目的探讨亚甲基四氢叶酸还原酶（methylenetetrahydrofolate reductase，MTHFR）基因C677T、甲硫氨酸合成酶（methionine synthase，MS）基因A2756G和胱硫醚β-合成酶（cystathionine β-synthase，CBS）基因844ins68这3种基因突变在深静脉血栓发病中的意义。方法应用聚合酶链反应-限制性片段长度多态性方法对103例深静脉血栓患者和250名健康对照者进行MTHFR C677T、MS A2756G和CBS 844ins68基因多态性的分析，并进行基因型及等位基因频率的计数。对MTHFR C677T和MS A2756G两位点进行单倍型分析。结果MTHFR C677T TT基因型在深静脉血栓组的分布频率（27．2％）高于对照组（17．2％），经χ^2检验差异有统计学意义（P〈0．05）。MS A2756G AG基因型在深静脉血栓组的分布频率（9．7％）低于对照组（19．2％），经χ^2检验差异有统计学意义（P〈0．05）。单倍型分析显示病例组中677T-2756A单倍型频率明显高于对照组（P〈0．05），677C-2756A单倍型频率明显低于对照组（P〈0．05）。CBS 844ins68基因型在两组的分布频率差异无统计学意义。结论MTHFR C677T多态性中TT基因型可能是深静脉血栓形成的一个遗传风险因子，MS 2756 AG基因型可能会减少深静脉血栓的发生。677T-2756A单倍型可能是静脉血栓的危险因素，677C-2756A单倍型可能是静脉血栓的保护因素。CBS 844ins68基因突变可能存在种族或地域的差异。

Study on the association of polymorphisms in homocysteine metabolism related enzymes with deep venous thrombosis

OBJECTIVE: To explore the significance of gene mutation of methylenetetrahydrofolate reductase (MTHFR) C677T, methionine synthase (MS) 2756 AG and cystathionine beta-synthase (CBS) 844ins68 in the development of deep venous thrombosis. METHODS: One hundred and three cases of deep venous thrombosis (DVT group) and 250 healthy subjects (control group) were recruited in the study. The polymorphisms of MTHFR C677T, MS A2756G and CBS 844ins68 were detected by PCR-restriction fragment length polymorphism(PCR-RFLP). RESULTS: The prevalences of TT genotypes of MTHFR (C677T) between DVT group and normal control group had significant difference (27.2% vs 17.2%, P< 0.05), the prevalence of AG genotypes of MS A2756G in the DVT group was less than that in the control group (9.7% vs 19.2%, P< 0.05). The prevalence of 677T-2756A haplotype in the DVT group was higher than that in the control group (P< 0.05), the prevalence of 677C-2756A haplotype in the DVT group was less than that in the control group (P< 0.05). There were no significant differences in the prevalences of CBS 844ins68 mutation. CONCLUSION: The homozygote of MTHFR C677T (TT) may be a risk factor of DVT. MS A2756 G(AG) genotypes may reduce the development of DVT. The 677T-2756A haplotype may be a risk factor of DVT. The 677C-2756A haplotype may be a protective factor of DVT. The prevalence of gene mutation of CBS 844ins68 might vary with different ethnic group or geographic regions.