江苏地区5776例孕妇脊髓性肌萎缩症携带者筛查及产前诊断

Carrier screening and prenatal diagnosis for spinal muscular atrophy in 5776 pregnant women from Jiangsu region

目的对江苏地区5776例孕妇进行脊髓性肌萎缩症(SMA)的携带者筛查,确定本地区SMA的携带频率,通过对高风险胎儿进行产前诊断,减少SMA患儿的出生。方法荧光定量PCR法检测SMN1基因第7和第8外显子的拷贝数,筛查SMA携带者,并通过多重连接依赖探针扩增技术(MLPA)对高风险胎儿进行产前诊断。结果对16549例孕妇进行SMA携带者筛查的宣教,其中5776例孕妇自愿接受携带者筛查,接受率约为34.9%。5776例孕妇中,共筛查到100例孕妇(100/5776,1.73%)携带SMN1基因E7单拷贝或E7和E8单拷贝,其中E7和E8单拷贝的孕妇有93例,单纯E7单拷贝有7例,携带者频率为1∶58。经遗传咨询,100例携带者中,91例配偶(91/100,91%)接受SMA筛查,结果提示3对夫妇同时为SMA携带者,并且对3例高风险胎儿进行了产前诊断,最终提示这3个胎儿均为SMN1基因单拷贝,即SMA携带者。结论荧光定量PCR技术适用于大样本量的人群携带者筛查,确定了江苏地区人群的SMA携带频率,并且对于高风险胎儿进行产前诊断,避免SMA患儿的出生,对出生缺陷的防控具有重要的临床意义。

Objective:To perform carrier screening for spinal muscular atrophy (SMA) among 5776 pregnant women from Jiangsu province and determine the carrier frequency of this region.To conduct the prenatal diagnosis for high-risk fetuses.Method:Real-time quantitative PCR (qPCR) was used to detect the copy number of SMN1 gene and Multiplex ligation-dependent probe amplification (MLPA) was used to prenatal diagnosis for the couples whom were both SMA carriers.Results:Of 16549 pregnant women,5776 women accepted the screening program and the accepted rate was 34.9%.A total of 100 pregnant women were identified as carriers,indicating a carrier prevalence of approximately 1∶58 in the population.After detailed genetic counseling,91 paternal partners were recalled and tested.The results showed that 3 couples were both SMA carriers.The prenatal diagnosis was implemented in 3 couples and 3 fetuses were all SMA carriers.Conclusion:It is the first large-scale carrier screening for SMA carriers in Jiangsu province.qPCR can effectively screen the carriers of SMA and the following pregnant diagnosis for high-risk fetus may reduce the rate of SMA affected births.