Department of Obstetrics and Gynecology, Meir Medical Center, Kfar Saba, Israel.
Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
J Perinat Med. 2020 Apr 28;48(6):553-558. doi: 10.1515/jpm-2020-0048.
Chromosomal microarray analysis (CMA) is the method of choice for genetic work-up in cases of fetal malformations. We assessed the detection rate of CMA in cases of abnormal fetal head circumference (HC).
The study cohort was based on 81 cases of amniocenteses performed throughout Israel for the indication of microcephaly (53) or macrocephaly (28), from January 2015 through December 2018. We retrieved data regarding the clinical background, parental HCs and work-up during the pregnancy from genetic counseling summaries and from patients' medical records.
There was only one likely pathogenic CMA result (1.89%): a 400-kb microdeletion at 16p13.3 detected in a case of isolated microcephaly. No pathogenic results were found in the macrocephaly group. Most fetuses with microcephaly were female (87.8%), while the majority with macrocephaly were males (86.4%).
The results imply that CMA analysis in pregnancies with microcephaly may carry a small yield compared to other indications. Regarding macrocephaly, our cohort was too small to draw conclusions. In light of the significant gender effect on the diagnosis of abnormal HC, standardization of fetal HC charts according to fetal gender may normalize cases that were categorized outside the normal range and may increase the yield of CMA for cases of abnormal HC.
染色体微阵列分析（CMA）是胎儿畸形遗传研究的首选方法。我们评估了 CMA 在异常头围（HC）病例中的检测率。
该研究队列基于 2015 年 1 月至 2018 年 12 月期间在以色列进行的 81 例羊膜穿刺术，指征为小头畸形（53 例）或大头畸形（28 例）。我们从遗传咨询摘要和患者病历中检索了有关临床背景、父母 HC 和妊娠期间检查的数据。
仅发现一个可能的致病性 CMA 结果（1.89%）：在一例孤立性小头畸形病例中检测到 16p13.3 处的 400-kb 微缺失。大头畸形组未发现致病性结果。大多数小头畸形胎儿为女性（87.8%），而大多数大头畸形胎儿为男性（86.4%）。
结果表明，与其他指征相比，CMA 分析在小头畸形妊娠中的检出率可能较低。关于大头畸形，我们的队列太小，无法得出结论。鉴于异常 HC 诊断中性别影响显著，根据胎儿性别对胎儿 HC 图表进行标准化可能会使归类于正常范围之外的病例正常化，并可能增加异常 HC 病例的 CMA 检出率。
