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

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。

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

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.