应用多重竞争性PCR联合毛细管电泳技术进行脊髓性肌萎缩症携带者筛查

Application of multiplex competitive PCR combined with capillary electrophoresis in carrier screening of spinal muscular atrophy

脊髓性肌萎缩症(spinal muscular atrophy,SMA)是一种常染色体隐性遗传、儿童致死性神经系统疾病。SMA致病基因为运动神经元存活基因(survival motor neuron1,SMN1)。虽然检测SMN1基因拷贝数的方法众多,但目前适于大规模人群筛查的技术较少。为寻求一种快速准确的实验技术可以用于人群中SMA携带者的大规模筛查,了解区域人群携带情况及常见变异的分布,本研究应用多重竞争性PCR联合毛细管电泳技术检测12例SMA患者及其父母SMN1基因拷贝数,同时对江苏地区151例健康孕妇人群SMN1基因进行拷贝数检测,并通过多重连接依赖探针扩增(multiplex ligation-dependent probe amplification,MLPA)技术验证检测结果。多重竞争性PCR联合毛细管电泳技术结果与MLPA结果一致,显示12例SMA患者均为SMN1基因零拷贝,其父母的SMN1基因拷贝数均为单拷贝,151例健康人群中检测出SMN1基因单拷贝3例(即SMA携带者),占2.0%;SMN1基因双拷贝134例,占88.7%;SMN1基因大于双拷贝14例,占9.3%。因此,多重竞争性PCR联合毛细管电泳技术作为一种快速、简便和准确的检测技术具有着应用于人群中SMA携带者的大规模筛查的潜力。

Spinal muscular atrophy(SMA)is an autosomal recessive,fatal neurological disorder in children.The pathogenic gene of SMA is survival motor neuron1(SMN1).There are many methods to detect SMN1 gene copy number,but few techniques are suitable for large-scale population screening.In order to find a rapid and accurate experimental technique for mass screening of SMA carriers in the population,the SMN1 gene copy number of 12 SMA patients and their parents was analyzed by multiplex competitive PCR combined with capillary electrophoresis.Meanwhile,the copy number of SMN1 gene in 151 healthy pregnant women in Jiangsu was screened with the MLPA technology to confirm their copy number of the SMN genes.The results showed that the 12 SMA patients had 0 copy of SMN1 gene,and all their parents had 1 copy of SMN1 gene only.Among 151 healthy subjects,3 cases(2.0%)had 1 copy of SMN1 gene,and hence designated as SMA carriers.One hundred and thirty-four cases(88.7%)had 2 copies of the SMN1 gene.There were 14 cases(9.3%)with more than 2 copies of the SMN1 gene.Therefore,multiplex competitive PCR combined with capillary electrophoresis is a rapid,simple and accurate method for the detection of SMA carriers;and potentially applicable to mass screening of SMA carriers in the population.