孤独症儿童亚甲基四氢叶酸还原酶基因C677T多态性分析

Association methylenetetrahydrofolate reductase gene C677T polymorphism with autism children

【目的】探讨孤独症儿童亚甲基四氢叶酸还原酶(methylenetetra-hydrofolate reductase,MTHFR)基因C677T多态性,为孤独症病因的寻找提供实验依据。【方法】采用限制性片段长度多态性聚合酶链反应(polymerase chain reaction-restriction fragment length polymorphism,PCR-RFLP)和基因测序的方法,对98例孤独症儿童与性别年龄匹配的70例对照组儿童的MTHFR基因C677T多态性进行分析。【结果】病例组(TT和CT为突变基因型)突变率为46.9%,对照组(TT和CT)突变率为14.3%,差异有统计学意义(χ2=19.59,P<0.005)。病例组与对照组的C、T等位基因频率相比差异有统计学意义(χ2=24.38,P<0.0005)。对病例组与对照组的基因型突变率差异进行多重比较,TT基因型和CT基因型的突变率与CC基因型相比差异均有统计学意义(χ2=10.12和19.76,P均<0.0125),而TT基因型突变率与CT基因型突变率在病例组和对照组中的分布无统计学意义(P>0.0125)。【结论】MTHFR基因C677T突变可能是儿童孤独症发病的遗传危险因素。

A total of 98 cases with autism and 70 controls which randomly selected were matched with the age and sex. Analysis of the polymorphism was done using the polymerase chain reaction-restriction fragment length polymorphism（PCR- RFLP）method and confirmed by direct sequencing. [Results] The rate of mutation（TT and CT genotype）in the case group（46.9 %） was significantly higher than control group（14.3 % ）（X^2= 19.59, P〈0. 005）. There was significant difference of C allele and T allele frequencies between the case group and the control group（X^2 = 24. 38, P〈0. 0005）. Partitions of X2 method was used to analyze the rate of genotype mutation between the case group and control group, both TT and CT genotypes mutation rate showed a significant statistic difference when they compared with CC genotype（X^2= 10.12,19.76, P all〈0. 0125） ; the rate of mutation of CT genotype and TT genotype showed no difference（P〉0. 0125）. [Conclusions] These findings indicate that the polymorphisms of MTHFR C677T genes may be a risk factor for autism.