单核苷酸多态性微阵列分析在产前基因诊断中的应用价值

Clinical value of single nucleotide polymorphism array for prenatal genetic diagnosis

目的评价单核苷酸多态性微阵列分析技术(single nucleotide polymorphism array,SNP array)在产前基因诊断中的临床应用价值。方法选择2016年1月至2017年2月在佛山市妇幼保健院产前诊断中心就诊的单胎孕妇进行遗传咨询,238例自愿进行产前诊断的孕妇抽取羊水或脐血进行常规G显带染色体核型分析,对其中染色体核型分析正常的143例病例进一步行SNP array,对SNP array确认拷贝数变异(copy number variant CNV)的病例,同时检测双亲样本,以明确变异的遗传性质及相关临床意义。结果染色体核型分析正常的143例病例行SNP array,检出7例致病性CNVS(4.9%),其中有1例单亲二倍体,2例临床意义不明确的CNVS(1.4%)。对这9例胎儿的双亲进行SNP array均未发现异常。结论 SNP array技术较传统的染色体核型分析方法能显著提高染色体拷贝数异常的检出率。SNP array技术是重要的产前基因诊断方法,可以尽可能的查找胎儿的遗传学病因,有利于产前临床咨询中正确评估胎儿的预后,为孕妇是否继续妊娠提供更客观的理论依据。

Objective：To evaluate the usefulness of single nucleotide polymorphism array（SNP array）for prenatal genetic diagnosis.Methods：Singleton fetuses were had prenatal genetic counseling at the center of prenatal diagnosis of Foshan Maternal and Child Health care Hospital from January 2016 to February 2017. 238 fetuses were performed invasive prenatal diagnosis（cord blood and amniotic fluid）for chromosome karyotype. Among them,143 normal cases were detected by SNP array. The cases were confirmed copy number variations by SNP array,the parental blood specimens were collected for assisting the genetic origin of variations and comfirmed the clinical significance of variations.Results：7（4.9%）pathogenic CNVs（include 1 uniparental disomy）and 2（1.4%）variants of unknown significance were detected by SNP array among 143 normal chromosome karyotype analysis. The 9 cases parents,SNP array results were normal. Conclusion：SNP array technology can significantly increase the detection rate of abnormal copy number variations compared with traditional chromosome karyotype. SNP array is an important prenatal genetic diagnostic tool for exploring possible genetic causes. This approach can provide additional information for prenatal genetic counseling and risk assessment. Furthermore,the detection of virulence gene before the period of fetal viability can provide parents with the option to consider termination of pregnancy.