脊髓性肌萎缩症携带者筛查及产前诊断结果分析

Analysis of Screening and Prenatal Diagnosis Results of Spinal Muscular Atrophy Carriers

目的 探索SMA携带者筛查及产前诊断的临床意义。方法 运用实时荧光定量PCR技术进行SMN1基因7号外显子(E7)拷贝数缺失检测,并对结果为阳性的孕妇其配偶进行检测,夫妇均为携带者对胎儿行产前诊断。结果 2472例孕妇共检出SMN1基因E7纯合缺失1例,携带者34例,携带率约为14%。SMA患者女儿诊断为杂合缺失携带者。召回配偶18例,其中1对夫妇检出均为为SMN1基因E7杂合缺失,对其胎儿进行产前诊断未检测到明确致病变异。1例SMA先证者家庭再生育发现:先证者为SMN1基因E7纯合缺失,先证者母亲及父亲为SMN1基因杂合缺失,二胎进行SMA产前诊断,未检测到明确致病变异。结论 本研究通过开展孕妇携带者筛查,可为当地SMA的遗传咨询和产前诊断提供理论依据,并对高风险胎儿使用多技术平台进行产前诊断,可有效避免SMA患儿的出生,对出生缺陷防控具有重要临床指导意义。

Objective To explore the clinical significance of screening and prenatal diagnosis of SMA carriers.Methods Real-time fluorescence quantitative PCR was used to detect copy number deletion of exon 7(E7)of SMN1 gene,and the spouses of pregnant women with positive results were detected,and the couple were both carriers for prenatal diagnosis of the fetus.Results Among 2472 pregnant women,there were 1 homozygous deletion of SMN1 gene E7 copy number,34 heterozygous deletion(carriers),with a carrying rate of about 1.4%.Daughter of SMA patients was diagnosed as carriers of heterozygosity loss.18 spouses were recalled,among which 1 couple was found to be heterozygotic deletion of SMN1 gene E7,and no definite pathogenic variation was detected in the prenatal diagnosis of their fetuses.The family rebirth of one SMA proband found that the proband had a homozygous deletion of the SMN1 gene E7,and the mother and father of the proband had a heterozygous deletion of the SMN1 gene.The second child underwent SMA Prenatal testing,and no clear pathogenic variation was detected.ConclusionThis study can provide theoretical basis for Genetic counseling and Prenatal testing of local SMA by carrying out carrier screening of pregnant women,and use multi technology platforms for Prenatal testing of high-risk fetuses,which can effectively avoid the birth of SMA children,and has important clinical significance for the prevention and control of birth defects.