染色体微阵列分析技术在超声异常胎儿产前遗传学诊断中的应用价值

Application value of chromosome microarray analysis in prenatal genetic diagnosis of abnormal fetus detected by ultrasound

目的探究染色体微阵列分析(CMA)技术在超声异常胎儿产前遗传学诊断中的应用价值.方法选取2017年3月至2019年12月就诊于我院的145例超声检测发现胎儿异常的孕妇,均进行常规染色体核型分析和CMA检测,分析单核苷酸多态性微阵列(SNP array)检测结果,并对致病CMA结果进行分析.结果145例超声异常的胎儿中,检出非整倍体8例,检出率5.52%;≥10Mb染色体重复/缺失5例,检出率3.45%;<10Mb染色体微重复/缺失11例,检出率7.59%.121例核型正常的胎儿中,致病性基因拷贝数变异(CNV)、临床意义不明确CNV(VOUS)、良性CNV分别占7.44%、88.43%、4.13%.9例致病CNV经CMA检测出心脏畸形伴变异型Dandy-Walker畸形1例、心脏畸形伴DiGeorge综合征2例、心脏畸形1例、肺发育畸形1例、双侧侧脑室扩张伴小脑横径小于正常预测值M-2.8SD1例、双侧侧脑室增宽伴小脑测值小于正常预测值M-3SD1例、胎儿生长受限伴鼻骨缺失1例,胎儿生长受限1例.结论CMA技术可有效发现超声异常胎儿的染色体微重复/微缺失,对产前遗传学诊断具有重要价值.

Objective To explore the application value of chromosome microarray analysis(CMA) in prenatal genetic diagnosis of abnormal fetus detected by ultrasound. Methods A total of 145 cases of pregnant women with fetal abnormalities detected by ultrasound in our hospital from March 2017 to December 2019 were selected and all underwent routine chromosome karyotype analysis and CMA detection.The results of single nucleotide polymorphism microarray(SNP array) and the results of pathogenic CMA were analyzed. Results Among the 145 abnormal fetuses detected by ultrasound, 8 cases of aneuploidy were detected, with a detection rate of 5.52%;5 cases of chromosome duplication/deletion ≥10 Mb were detected, with a detection rate of 3.45%. There were 11 cases of <10 Mb chromosome microduplication/deletion, and the detection rate was 7.59%. Among the 121 fetuses with normal karyotype, pathogenic gene copy number variation(CNV), clinically ambiguous CNV(vous) and benign CNV accounted for 7.44%, 88.43% and 4.13% respectively. Nine cases of pathogenic CNV were detected by CMA, including one case of cardiac malformation with variant Dandy Walker malformation, two cases of cardiac malformation with DiGeorge syndrome, one case of cardiac malformation, one case of pulmonary developmental malformation, one case of bilateral lateral ventricular dilatation with cerebellar transverse diameter less than the normal prediction value M-2.8 SD, one case of bilateral lateral ventricular widening with cerebellar measurement value less than the normal prediction value M-3 SD, and one case of fetal growth restriction with nasal bone loss, and one case of fetal growth restriction. Conclusion The CMA technology can effectively detect chromosome microduplication/microdeletion of abnormal fetus detected by ultrasound, and it is of great value for prenatal genetic diagnosis.