亚甲基四氢叶酸还原酶多态性与早期妊娠丢失风险的关系研究

Association between MTHFR C677T and risk of early pregnancy loss

目的探讨亚甲基四氢叶酸还原酶(MTHFR)基因C677T位点多态性与早期妊娠丢失风险的关系。方法采用PCR-限制性片段长度多态性(PCR-RFLP)方法检测232例妊娠13^(+6)周之内曾有不良孕史及先兆流产史的患者(病例组)和369例孕前检查的正常妇女(对照组)MTHFRC677T基因多态性。结果不良孕史及先兆流产史患者MTHFRC677T位点3个基因型多态性与对照组有显著性差异(x^2=37.768,P<0.05);与CC基因型个体相比,TT基因型的个体发生早期妊娠丢失的风险高达3.596倍(OR=3.596,95%CI:2.232~5.794),CT基因型的个体发生早期妊娠丢失的风险为3.277倍(OR=3.277,95%CI:2.137~5.026)。病例组T等位基因频数分布显著高于C等位基因频数分布(57.1%vs.40.1%,x^2=33.094,P<0.05,OR=1.988,95%CI:1.571~2.517)。结论 MTHFR C677T突变可能是早期妊娠丢失的遗传易感性因素。

Objective To discuss the relationship between methylene tetrahydrofolate reductase （MTHFR） C677T and early pregnancy loss risk. Methods PCR-RFLP method was used to detect the MTHFRC677T gene polymorphism of 232 patients with adverse pregnant history or threatened abortion history within 13 ＋6 week （case group） and 369 normal women checked before pregnancy （control group）. Results There was significant difference in the polymorphism of three genotypes of MTHFRC677T site between case group and control group （X2 = 37. 768,P 〈 0.05 ）. The risk of early pregnancy loss among the patients with TT gene type significantly increased and reached to 3. 596 times compared with CC gene type （ OR = 3. 596, 95 % CI ： 2. 232 - 5. 794）, and that among patients with CT gene type showed 3. 277 times （OR = 3. 277,95% CI： 2. 137 -5. 026）. The allelic frequency of T was significantly higher than C in case group （57.1% vs 40.1% ,A2 =33. 094,P 〈0.05, OR = 1. 988,95% CI： 1. 571 -2. 517）. Conclusion MTHFR C677T mutation might be the genetic susceptibility factor leading to early pregnancy loss.