叶酸代谢关键酶基因多态性与唐氏综合征发生关系的研究

目的 研究叶酸代谢中关键酶亚甲基四氢叶酸还原酶基因(MTHFR C677T)及蛋氨酸合成酶还原酶基因(MTRRA66G)多态性与唐氏综合征发生的关系.方法 采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)法对32例唐氏综合征患儿母亲及70例未生育该种患儿的女性MTHFR C677T、MTRR A66G进行基因分析.比较各组基因型和等位基因频率分布有无差异.结果 MTHFR C677T突变型等位基因(T)频率,MTRR A66G突变型等位基因(G)频率在实验组和对照组中有显著性差异,CC、TT、GG基因型频率分布差异有显著性意义(P＜0.05).结论 MTHFR C677T、T677T基因型、MTRR G66G基因型增加了唐氏综合征的发生风险,MTHFR C677C基因型可能是降低唐氏综合征发生的保护性因素.

Study on the relationship between genetic polymorphisms in MTHFR C677T,MTRR A66G and development of Down syndrome

Objective To explore the relationship between genetic polymorphisms in methylenetetrahydrofolate reductase(MTHFR),methionine synthase reductase(MTRR),the central enzymes in folate metabolism that affects DNA methylation and synthesis,and the risk of Down syndrome.Methods Genomic DNA was isolated from the peripheral lymphocytes of 32 mothers of children with Down syndrome and 70 age matched control subjects.Polymerase chain reaction and restriction fragment length polymorphism were used to examine the polymorphisms of MTHFR C677T,MTRRA66G and the relation between these genotypes and risk of Down syndrome was analyzed.Results It was obvious difference between experiment and control group in MTHFR gene C677T mutation allele(T),MTRR gene A66G mutation allele(G) frequency(P<(0.05),for both),MTHFR 677 TT and CC had obvious difference(P<(0.05)).Conclusion MTHFR and MTRR gene mutation allele are related to Down syndrome,CT,TT,GG gene mutation type increased the risk of Down syndrome and CC type perhaps were the protective factor in decreasing the risk of Down syndrome.