染色体微阵列分析技术在侧脑室增宽胎儿产前诊断中的应用价值

目的 应用染色体微阵列分析技术(CMA)在全基因组水平分析侧脑室增宽胎儿的遗传学病因,探讨胎儿侧脑室增宽与染色体拷贝数变异(CNVs)的相关性及CMA检测在侧脑室增宽胎儿产前诊断中的应用价值.方法 选取2015年1月-2016年11月在第四军医大学西京医院就诊并接受介入性产前诊断的70例孕中/晚期超声提示胎儿侧脑室宽大于1.0cm且标准G显带染色体核型分析正常或G显带染色体核型分析不能确定的染色体异常胎儿样本,应用Affymetrix CytoScanTM750k芯片进行CMA检测,根据相关生物信息学数据库对CMA检测结果进行全面分析,并定期复查胎儿的发育情况,随访妊娠结局及胎儿出生后的生长发育状况.结果 在70例侧脑室增宽胎儿中,CMA检测发现9例胎儿存在致病性CNVs,3例胎儿存在意义不明确、可能致病的CNVs,1例胎儿存在意义不明确、可能致病的杂合性缺失(LOH).在70例侧脑室增宽胎儿中,重度非孤立性侧脑室增宽6例,其中致病性CNVs 2例(33.3％,2/6);重度孤立性侧脑室增宽3例,未检出致病性CNVs,意义不明确、可能致病CNVs 1例(33.3％,1/3);轻度非孤立性侧脑室增宽31例,其中致病性CNVs 6例(19.4％,6/31),意义不明确、可能致病CNVs 2例(6.5％,2/31);轻度孤立性侧脑室增宽30例,其中致病性CNVs 1例(3.3％,1/30),意义不明确、可能致病CNVs 1例(3.3％,1/30).结论 CMA可更有效地检测出传统核型分析无法识别的微缺失、微重复等染色体异常,对侧脑室增宽的胎儿进行CMA检测能够提高异常检出率,对临床产前诊断及遗传咨询具有重要价值.

Application value of chromosomal microarray analysis in prenatal diagnosis of lateral ventriculomegaly fetuses

Objective To analyze the genetic etiology of lateral ventriculomegaly fetal on the genome-wide level with chromosomal microarray analysis (CMA),and investigate the relationship between copy number variations (CNVs) and lateral ventriculomegaly and the application value of CMA in prenatal diagnosis of fetuses with lateral ventriculomegaly.Methods Seventy fetuses with lateral ventriculomegaly but normal or uncertain karyotype were selected and invasive prenatal diagnosis was performed in Xi Jing Hospital of the Fourth Military Medical University from Jan.2015 to Nov.2016.Microarray testing was performed using Affymetrix CytoScanTM 750k arrays and the results were analyzed according to biological information science database.The fetal development was regularly inspected,and follow up was conducted to find out the pregnancy outcome and fetal postnatal conditions.Results In 70 cases of lateral ventriculomegaly fetuses,there were 9 fetuses with pathogenic copy number variations (CNVs),3 fetuses with likely pathogenic CNVs and 1 fetus with likely pathogenic 1 oss of heterozygosity (LOH).During the 70 fetuses with lateral ventriculomegaly,2 pathogenic CNVs were detected in 6 fetuses with severe and non isolated lateral ventriculomegaly (33.3％).Pathogenic CNVs was not detected but 1 likely pathogenic CNV was detected in 3 fetuses with severe and isolated lateral ventriculomegaly (33.3％).Six pathogenic CNVs were detected in 31 mild and non isolated lateral ventriculomegaly (19.4％),and 2 likely pathogenic CNVs were also detected in these group (6.5％).One pathogenic CNV and 1 likely pathogenic CNV were detected in 30 fetuses with mild and isolated fetal lateral ventriculomegaly.Conclusions CMA can identify chromosome abnormality microdeletion/microduplication which was unrecognizable by conventional karyotyping analysis.The application of CMA may increase the detection rate of pathogenic CNVs in fetuses with lateral ventriculomegaly,and benefit evaluation of fetal prognosis in prenatal genetic counselling.