Department of Genetics, Hadassah-Hebrew University Medical Center.
Faculty of Medicine, The Hebrew University of Jerusalem.
Curr Opin Obstet Gynecol. 2021 Apr 1;33(2):143-147. doi: 10.1097/GCO.0000000000000690.
Chromosomal-microarray analysis (CMA) is the first-tier test in pregnancies with structural malformations. Accumulating data show that pathogenic copy number variants (CNVs) can also be identified in structurally normal fetuses. We set out to summarize the published data on the diagnostic yield of CMA in structurally normal fetuses.
Six studies summarize a total of 29,612 prenatal CMAs performed in structurally normal fetuses. The incidence of highly penetrant pathogenic/likely pathogenic CNVs is 0.4-2.5%. Variability was demonstrated in the timing of CMA testing and type of CNVs classified as pathogenic. The incidence of variants of uncertain significance is 0.4-5.4%. The prevalence of susceptibility loci is 0.3-0.7% when specified, and the incidence of CNVs associated with late onset disease is 0.1%.
With a frequency of abnormal CNVs of 1:40 to 1:250 in structurally normal fetuses, it is recommended that all pregnant women be informed of the possibility to have CMA performed, even in the absence of malformations. Information should also be provided about uncertain and secondary findings.
染色体微阵列分析（CMA）是结构畸形妊娠的一线检测方法。越来越多的数据表明，在结构正常的胎儿中也可以识别出致病性拷贝数变异（CNVs）。我们旨在总结 CMA 在结构正常胎儿中的诊断效果的已发表数据。
6 项研究总结了总共 29612 例在结构正常胎儿中进行的产前 CMA。高度外显的致病性/可能致病性 CNVs 的发生率为 0.4-2.5%。在 CMA 检测的时间和分类为致病性的 CNVs 的类型方面存在变异性。意义不明的变异的发生率为 0.4-5.4%。在特定情况下，易感基因座的患病率为 0.3-0.7%，与迟发性疾病相关的 CNVs 的发生率为 0.1%。
在结构正常的胎儿中，异常 CNVs 的频率为 1:40 至 1:250，建议所有孕妇都被告知有可能进行 CMA，即使没有畸形。还应提供有关不确定和次要发现的信息。
