中国上海地区4719名孕妇脊髓性肌萎缩症携带者筛查

Carrier screening for spinal muscular atrophy in 4719 pregnant women in Shanghai region

目的对中国上海地区4719名孕妇进行脊髓性肌萎缩症携带者的筛查，为遗传咨询及进一步产前诊断提供依据。方法应用多重PCR结合变性高效液相色谱技术进行SMN1及SMN2基因拷贝数的检测，筛查出SMN1拷贝数为1的脊髓性肌萎缩症携带者。结果在4719份样品中共检测出SMA携带者90例。女性携带者频率为1．9％，其中SMN1杂合缺失占1．2％。由SMN1基因转换成SMN2基因者占0．6％。结论确定上海地区女性脊髓性肌萎缩症携带者的频率可为遗传咨询及产前诊断提供理论依据，并降低脊髓性肌萎缩症患儿的出生率。

Objective Spinal muscular atrophy （SMA） is a common and fatal autosomal recessive disorder. Approximately 94% of SMA patients are caused by homozygous deletion of SMN1 gene. SMA carrier screening is recommended considering the high carrier frequency （1 in 35-50） as well as severity of the disease. Methods A prospective population-based cohort study was carried out on 4719 pregnant women from Shanghai region. Copy numbers of SMN1 and SMN2 genes were effectively determined with denaturing high performance liquid chromatography （DHPLC） technique. The method has detected 94% of SMA cases with deletion or conversion of the SMN1 genes. Results Ninety SMA carriers with only one copy of the SMN1 gene were identified among the 4719 pregnant woman. The carrier rate was 1.9%. Respectively, 1. 2 % and 0.6 % of the carriers were caused by SMN1 gene deletion and SMN1 gene conversion. Conclusion Through this study, we have determined the frequency of SMA mutation carriers in a population of pregnant women. The result may provide a basis for genetic counseling in order to reduce the rate of SMA affected births