【摘要】 目的　探讨叶酸、维生素B1 2 (VB1 2 )、血浆总同型半胱氨酸 (tHcy)、5 ,10 亚甲基四氢叶酸还原酶 (MTHFR)活性及其热敏感性基因型间的相互关系。方法　研究对象为 3 4例生育神经管畸形(NTDs)儿的母亲及 4 2例生育正常儿的母亲 ,检测指标包括tHcy、红细胞叶酸、血清叶酸和VB1 2 、MTHFR酶活性及热敏感性基因型。结果　tHcy、红细胞叶酸、血清叶酸在病例组与对照组间差异无统计学意义 ;NTDs患儿母亲VB1 2 显著低于正常儿母亲 ;tHcy与红细胞叶酸呈显著负相关 ;MTHFR热敏感性基因纯合突变组tHcy显著高于杂合突变和纯合野生组 ;血清维生素水平在MTHFR各基因型间差异无显著性 ;叶酸较低组tHcy略高于叶酸较高组 ,并与MTHFR酶活性呈显著负相关。结论　体内tHcy增高与MTHFR热敏感性基因纯合突变、酶活性下降有关 ;体内叶酸水平高低影响tHcy与MTHFR酶活性相关性。更多还原

【Abstract】 Objective Tostudyrelationshipbetweenserumandredbloodcell(RBC)folate ,serum vitaminB1 2 (VB1 2 ) ,totalplasmahomocysteine (tHcy) ,thermolabilegenotypes,andactivityofmethylene tetrahydrofolatereductase (MTHFR) .Methods Thirty fournon pregnantandhealthymotherswhogavebirthto babieswithneuraltubedefects (NTDs)and 4 2motherstonormalbabiespreviouslywerechosen .PlasmatHcy, RBCandserumfolate ,serumVB1 2 ,activityofMTHFRandthermolabilegenotypesweredeterminedforallof them .Results TherewasnosignificantdifferenceinplasmatHcy ,RBCandserunfolatebetweencaseand controlgroups.SerumVB1 2 wassignificantlylowerinmothersofbabieswithNTDsthaninthosewithnormalones. PlasmatHcycorrelatedwithRBCfolateinversely (P <0 .0 5 ) .MeanplasmatHcyforthermolabilehomozygous mutationofMTHFRwassignificantlyhigherthanthatforeitherheterozygousmutationorwildhomozygousmutation (P <0 .0 0 1) .TherewasnosignificantdifferenceinserumfolatebetweengroupswithvariedMTHFRgenotypes. PlasmatHcywasslightlygreaterinthosewithlowerserumfolatethaninthosewithhigherone ,andcorrelated inverselywithactivityofMTHFR .Conclusions IncreaseinplasmatHcycorrelateswithhomozygousmutationof thermolabileMTHFRanddecreaseinactivityofMTHFR .Higherleveloffolateinthebodycaninterferethe relationshipbetweenplasmatHcyandactivityofMTHFR .更多还原