Value of chromosomal microarray analysis for genetic evaluation of fetal ultrasound abnormality

Abstract

Objective To evaluate the value of chromosomal microarray analysis (CMA) for genetic evaluation of fetal ultrasound abnormality.

Methods A total of 180 pregnant women with fetal abnormality detected by prenatal ultrasound diagnosis in the first trimester during the period from January 2020 through May 2022 were enrolled as the study subjects. All prenatal fetal screening samples were subjected to G-band karyotyping and CMA.

Results G-band karyotyping detected normal karyotypes in 168 samples (93.85%) and abnormal karyotypes in 11 samples (6.15%), and CMA detected 17 positive samples (9.44%) and 163 negative samples (90.56%). The seventeen positive samples included 11 pathogenic copy number variations (CNVs) and 6 variants of unknown significance (VOUS), and there were 11 CMA-positive results consistent with G-band karyotyping, and 6 additional pathogenic CNVs mainly included microdeletion and microduplication syndromes. The detection rates of pathogenic CNVs were 11.11%, 2.63%, 2.78%, 4.00%, 0, 0, 11.11% and 0 among the fetuses with abnormal structure of the cardiovascular system, the lymphatic system, the nervous system, the digestive system, the cranial and face system, the skeletal system, the urinary system, and other system (χ ² = 8.188, P = 0.316). All eleven fetuses with pathogenic CNVs detected by CMA were all induced for abortion.

Conclusion CMA improves the detection of genetic abnormality among fetuses with ultrasound abnormality in relative to G-band karyotyping, which is feasible for prenatal cytogenetic diagnosis among fetuses with ultrasound abnormality

Abstract

摘要： 目的 探索染色体微阵列技术(CMA)用于评估超声异常胎儿遗传学诊断中的应用价值。 方法 收集2020年 1月一2022年5月经产前超声诊断为孕早期胎儿异常的180例孕妇作为研宄对象, 对胎儿产前筛查样本进行G显带 核型分析和CMA检测。 结果 G显带核型分析结果提示正常核型168例(93.85%), 异常核型11例(6.15%)。CMA检测发现阳性结果17例(9.44%)、阴性结果163例(90.56%)。17例阳性结果包括11例致病性基因拷贝数变异 (CNV)、6例临床意义不明确的CNV(VOUS);其中11例与染色体核型分析结果一致, 并检出其他6例致病性CNV, 主要为微缺失和微重复综合征。心血管系统结构异常、淋巴系统结构异常、神经系统结构异常、消化系统结构异常、颅面系统结构异常、骨骼系统结构异常、泌尿系统结构异常、其他系统结构异常胎儿致病性CNV检出率分别为11.11%、2.63%、2.78%、4.00%、0、0、11.11%、0(χ ² = 8.188, P = 0.316)。11 例 CMA 检出为致病性 CNV 的胎儿均引 产。 结论 CMA相较于染色体核型分析可提高超声结构异常胎儿遗传学异常检出率, 值得临床上用于超声结构异常 胎儿产前细胞遗传学诊断。