唐氏综合征患儿母亲MTHFR C677T基因多态性及血浆叶酸、同型半胱氨酸水平的研究

Plasma Folate、Homocysteine and MTHFR C677T polymorphisms in the mother with Down syndrome children

目的研究浙南地区汉族妇女叶酸及代谢产物同型半胱氨酸水平、亚甲基四氢叶酸还原酶(MTHFR)基因C677T位点多态性与唐氏综合征(Down's Syndrome,DS)发生的关系。方法对84例已生育DS患儿的母亲(观察组)和120例生育过正常儿童的母亲(对照组)采用PCR扩增及DNA测序法检测亚甲基四氢叶酸还原酶基因MTHFR C677T单核苷酸多态性;免疫发光法检测叶酸(Folate)及循环酶法检测血浆同型半胱氨酸(Hcy)水平。结果 MTHFR 677 T基因及CT、TT基因型的频率两组无统计学意义(P>0.05)。对观察组与对照组的部分标本行血浆Folate与Hcy水平测定,观察组Folate水平显著高于对照组(t=-5.572,P<0.05);Hcy水平两组平均水平无统计学意义(t=0.152,P>0.05);Fo-late与Hcy水平呈负相关关系(r=-0.217,P<0.05)。观察组与对照组MTHFR 677CT、TT基因型与CC基因型Hcy水平比较均无统计学意义(P>0.05),观察组TT基因型Hcy水平比对照组有显著性升高(t=2.546,P<0.05)。结论本研究MTHFR C677T位点不是浙南地区汉族妇女DS的风险因素;DS母亲Folate水平高于对照组及MTHFR 677 TT基因型Hcy水平高于对照组,可能存在影响叶酸代谢的其他相关基因的多态性或营养的缺乏,有待进一步深入研究。

Objective： To investigate the relationships between the plasma Folate, Homocysteine, MTHFR C677T polymorphism in Chinese Han women from Souther Zhejiang province with Down syndrome children. Methods ： A case - control study was conducted. The polymorphisms of C677T in methylenetetrahydrofolate reduetase （ MTHFR ） was analysed in 84 mothers of children with DS （ the cases） and 120 matched mothers （the controls） by Polymerase Chain Reaction （PCR） and DNA sequencing; the levels of Folate were detected by chemiluminescence and Homocysteine （Hey） were detected by cycle enzyme assay. Results： The frequencies of MTHFR 677 T and CT, TT were higher in the cases than in the controls, but there was no significant differences （ P 〉 0. 05 ）. The levels of Folate in the cases were significant higher in the cases than in the controls （ t = - 5. 572, P 〈 0.05 ） ; There were no signifi- cant differences for the levels of Hcy in two groups ; there were negative correlation between the Folate levels and the Hey levels （ r = - 0. 217, P 〈 0.05 ）. The levels of Hcy in Homozygotes TT of MTHFR 677 were higher in the cases than in the controls （ t = 2. 546, P 〈 0. 05 ）. Conclusion： MTHFR C677T was not the risks factors of DS. Perhaps there were other gene mutation about Folate metabo- lism or nutrition deficiency to take charge the higher levels of Hcy in cases with Homozygotes TT of MTHFR 677 and the higher leves of Folate in the cases.