为确定神经管畸形发生是否与某些基因突变有关,利用扩增阻碍突变系统(am plificationrefractory m utation system ,ARMS)法对40例神经管畸形(NTDs)儿母亲和36例正常儿母亲的胱硫脒β合酶(cystathionine beta-synthase,CBS)的2个常见突变位点(第919位及第833位)核苷酸进行基因多态性分析。结果显示NTDs组和对照组G919A的纯合突变率分别为35% 和33% ,二者差异无显著性(P> 0.05);T833C的纯合突变率分别为20% 和8% ,二者差异亦无显著性(P> 0.05)。提示母亲的CBS基因型可能不是生育NTDs儿的直接病因 To determine whether the occurrence of neural tube defects was related to some gene mutations, 40 cases of neural tube defects (NTDs) and 36 normal children were treated with ARMS Two common mutation sites (919th and 833th) of cystathionine beta-synthase (CBS) were used to analyze the gene polymorphism. The results showed that the homozygous mutation rates of G919A in NTDs group and control group were 35% and 33%, respectively, with no significant difference (P> 0.05). The homozygous mutation rates of T833C were 20% and 8% respectively Also no significant (P> 0.05). Suggesting that the mother’s CBS genotype may not be the direct cause of fertility in NTDs