郏县汉族女性MTHFR基因C677T、A1298C位点与MTRR基因A66G位点的多态性分布

DISTRIBUTION OF MTHFR C677T,A1298C POLYMORDHISMS,AND MTRR A66G POLYMORPHISMS IN HAN WOMEN IN JIA COUNTY,CHINA

目的分析郏县汉族育龄女性叶酸代谢关键酶5,10-亚甲基四氢叶酸还原酶(MTHFR)基因和甲硫氨酸合成酶还原酶(MTRR)基因相关位点多态性分布的特点,旨在为孕妇增补叶酸提供参考。方法采集2017—2019年在郏县妇幼保健院接受孕期检查的554例女性的口腔黏膜细胞样本,提取DNA,采用相关PCR法对MTRR基因A66G位点、MTHFR基因A1298C、C677T位点多态性进行检测并分析。结果所有样本基因位点多态性分布符合遗传平衡定律。其中MTHFR基因C677T位点TT型、CT型、CC型占比分别为42.8%、43.3%、13.9%;MTHFR基因A1298C位点AA型、AC型、CC型占比分别为77.3%、22.0%、0.7%;MTRR基因A66G位点AA型、AG型、GG型占比分别为56.7%、36.6%、6.7%。郏县汉族育龄女性MTHFR基因C677T和A1298C两位点连锁有7种组合,频率最高的是TT/AA(42.8%),无TT/AC和TT/CC组合,两位点间存在强连锁不平衡(D′=0.984,r^(2)=0.233)。结论郏县汉族育龄女性MTHFR、MTRR基因位点多态性特征与其他地区汉族女性有所区别,具有地域特异性,其中MTHFR基因C677T位点中,TT基因型占比较高,如妊娠期女性为该基因类型,在其妊娠期间应适当增加叶酸量,并根据实际情况增加增补天数。

Objective To analyze the distribution characteristics of the gene polymorphisms of key enzymes related to folate metabolism[5,10-methylenetetrahydrofolate reductase(MTHFR)and methionine synthase reductase(MTRR)]in women of reproductive age of the Han nationality in Jia County,China,and to provide a reference for folate supplementation for pregnant women.Methods A total of 554 women who underwent examinations during pregnancy in Jia County Maternal and Child Health Hospital from 2017 to 2019 were enrolled.Oral mucosal cell samples were collected from them,followed by DNA extraction.PCR was used to examine MTRR(A66G)and MTHFR(A1298C and C677T)polymorphisms.Results The distribution of polymorphisms of all the samples accorded with the law of genetic equilibrium.The proportions of TT,CT,and CC genotypes at the C677T locus of the MTHFR gene were 42.8%,43.3%,and 13.9%,respectively.The proportions of AA,AC,and CC genotypes at MTHFR A1298C were 77.3%,22.0%,and 0.7%,respectively.The proportions of AA,AG,and GG genotypes at MTRR A66G were 56.7%,36.6%,and 6.7%,respectively.There were seven combinations of MTHFR C677T and A1298C genotypes among the Han women of reproductive age in Jia County.TT/AA was the most frequent combination,which accounted for 42.8%.No TT/AC or TT/CC combination was found.There was a strong linkage disequilibrium between the two loci(D′=0.984,r^(2)=0.233).Conclusion Different from those of Han women in other regions,Han women of reproductive age in Jia County show regional specificity in MTHFR and MTRR polymorphisms.There is a high proportion of the TT genotype at MTHFR C677T,with which genotype women should appropriately increase the dose and duration of folate supplementation according to actual situation during pregnancy.