甘肃地区13022例孕妇脊髓性肌萎缩症携带者筛查及产前诊断

Carrire screening and prenatal diagnosis for spinal muscular atrophy in 13022 pregnant women from Gansu region

目的对甘肃地区13022例孕妇进行脊髓性肌萎缩症(SMA)携带者筛查,分析本地区人群中运动神经元存活基因1(SMN1)携带率,对高风险胎儿进行产前诊断,旨在减少本地区SMA患儿的出生。方法采用实时荧光定量PCR法对孕妇进行SMN1基因E7/E8拷贝数相对定量检测,筛选携带者孕妇并对其配偶进行拷贝数检测,若双方同为携带者则通过多重连接探针扩增技术(MLPA)对高风险胎儿进行产前诊断。结果在13022例孕妇中,共检出236例SMA携带者(SMN1基因E7、E8杂合缺失217例,E7杂合缺失19例),携带者频率为1/56(1.81%)。检出夫妻双方均为SMA携带者4对,经过产前诊断,其中SMA携带者胎儿2例,患儿1例,正常胎儿1例。此外,对236例携带者孕妇进行SMN2基因E7/E8拷贝数检测,共检出39例为SMN2基因E7、E8重复,44例为SMN2基因E7、E8杂合缺失。结论分析了甘肃地区SMA突变类型及携带率,为本地区SMA遗传咨询及产前诊断提供数据支持,对携带者进行SMN2拷贝数的检测,可对甘肃地区SMA的筛查、诊断、用药提供新思路。

Objective A total of 13022 pregnant women in Gansu province were screened for spinal muscular atrophy(SMA)carriers,and the prevalence of motor neuron survival gene 1(SMN1)mutation in the population was calculated.Prenatal diagnosis of high-risk fetuses was performed to reduce the number of SMA born in this region.Methods Real-time fluorescence quantitative PCR was used to detect SMN1 gene E7/E8 copy number in pregnant women,and the spouses of pregnant women who were screened as carriers were also detected.If both partners are carriers,prenatal diagnosis of high-risk fetuses is performed by multi-junction probe amplification(MLPA).Results Among the 13022 pregnant women,a total of 236SMA carriers were detected(217 cases of E7 and E8 heterozygous deletion of SMN1 gene,and 19 cases of E7 heterozygous deletion),and the carrier frequency was 1/56(1.81%).Four couples were detected as SMA carriers.After prenatal diagnosis,there were 2 SMA carriers,1 child and 1 normal fetus.In addition,the copy number of SMN2 gene E7/E8 was detected in 236pregnant women with carriers.A total of 39 cases were detected with SMN2 gene E7 and E8 duplication,and 44 cases were detected with SMN2 gene E7 and E8 heterozygosity deletion.Conclusion The analysis of SMA mutation type and carrier rate in Gansu province can provide data support for SMA genetic counseling and prenatal diagnosis.The detection of SMN2 copy number in carriers can provide a new idea for the screening,diagnosis and medication of SMA in Gansu.