脊肌萎缩症的基因诊断和产前诊断

The gene diagnosis and the prenatal diagnosis of spinal muscular atrophy

目的:建立有效快速的脊肌萎缩症(SMA)的基因诊断和有脊肌萎缩症患儿生育史孕妇的产前诊断方法。方法:应用聚合酶链式反应和限制性片段多态性(PCR-RFLP)检测方法对87例疑似患儿SMN基因第7、8外显子进行缺失分析;通过PCR-RFLP和JK53CA1/2、D5S637和CATT1三个STR位点连锁分析技术对5例有脊肌萎缩症患儿生育史的孕妇进行产前诊断。结果:在87例疑似患儿中发现有30例患儿SMN基因第7、8外显子缺失,2例SMN基因第7外显子缺失,而在5例有SMA生育史孕妇产前诊断胎儿为SMA患者风险低,建议正常分娩。结论:PCR-酶切分析方法和STR连锁分析方法准确、简便,可作为脊肌萎缩症的基因诊断和产前基因诊断的方法。

Objective：To establish efficient and accurate methods for gene diagnosis and prenatal diagnosis of spinal muscular atrophy（SMA）.Methods：Polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP） was applied to analyze the deletion of SMN1 exon 7 and 8 in 87 children with clinically suspected SMA cases.PCR-RFLP and genetic linkage analysis of three SMN1 STR markers,JK53CA1/2,D5S637 and CATTI,were applied for prenatal prediction of SMA using amniotic fluid from 5 pregnant women who previously had a child with SMA.Results：Among 87 suspected cases,deletion of both exon 7 and exon 8 was detected in 30 cases,two cases showed deletion of exon 7 only,and no deletion of exon 7 and/or exon 8 was detected in the other 55 cases.Furthermore,the results of prenatal diagnosis indicated that 5 fetuses were predicted to be healthy.The follow-up result of these fetuses supported the prenatal diagnosis after births.Conclusion：These results suggest that PCR-RFLP and genetic linkage analysis offer efficient and accurate methods for genetic diagnosis and prenatal diagnosis of SMA.