QF-PCR对孕妇SMN1基因筛查并应用于产前诊断

目的：通过对孕妇人群中SMN1基因的第7以及第8外显子（E7、E8）缺失情况的筛查研究，建立起一种简便、准确、高通量、快速的产前筛查和诊断孕妇E7、E8缺失的方法，防止脊肌萎缩症（spinal muscular atrophy，SMA）患儿出生。方法：选择2014年12月—2017年10月就诊于天津市中心妇产科医院的孕中期妇女162例，采用荧光定量聚合酶链式反应法（QF-PCR）对孕妇进行SMN1基因E7、E8缺失情况筛查，对同为SMA携带者夫妇胎儿进行SMN1基因缺失检测，并用多重连接探针扩增技术（MLPA）验证。结果：在162例孕妇中共筛查出含有SMN1 E7杂合缺失的携带者6例，其中4例携带者配偶为E7和E8正常型，2例为E7和E8杂合缺失。夫妇双方均为SMA携带者的2例高危胎儿中，1例为E7、E8纯合缺失，1例为与其双亲相同的SMN1 E7、E8杂合缺失，与MLPA法检测结果相一致。结论：QF-PCR能够广泛应用于筛查SMA携带者孕妇，对避免出生缺陷具有重要的临床价值。

The Screening and Prenatal Diagnosis for SMN1 Gene in Pregnant Women

Objective：By conducting screening studies on the deletion mutations in exon 7 and exon 8 (E7, E8) of SMN1 gene in pregnant women, an accurate, rapid, simple, and high-throughput prenatal screening and diagnosis of this gene locus was established. SMA patients can be prevented. Methods：QF-PCR was used to screen the deletion of SMN1 gene E7 and E8 in 162 cases of women in mid-pregnancy. When the spouses were carriers of SMA pathogenic genes, fetal DNA was extracted to detect SMN1 gene deletion. The high-risk fetal MLPA genetic diagnosis was performed at the same time. Results：A total of 162 pregnant women were screened and the presence of SMN1 E7 heterozygous carriers were found in 6 cases. As for the QF -PCR test results of the carriers′ spouses，4 cases showed that E7 and E8 were all normal and 2 cases showed loss of heterogeneity. As to the two high-risk fetus whose both parents were SMA carriers，amniotic fluid DNA testing suggested that 1 fetus had E7 and E8 homozygous deletion, and the other one showed loss of heterogeneity. The results of MLPA were same with QF-PCR. Conclusions：QF-PCR can be used in the screening and diagnosis of SMA patients in large pregnant population. It has great clinical value to prevent the birth of SMA children.