Application of genome copy number variation sequencing combined with chromosome karyotype analysis in prenatal diagnosis / 中国医师进修杂志

ABSTRACT

Objective:To explore the application value of copy number variation sequencing(CNV-seq) combined with chromosome karyotyping technology based on next-generation sequencing technology in prenatal diagnosis.Methods:The subjects of the study were 329 pregnant women who underwent prenatal diagnosis at Dalian Municipal Women and Children′s Medical Center from January 2019 to June 2020. The amniotic fluid samples of these pregnant women were submitted for chromosome karyotype analysis, and CNV-seq testing was performed at the same time to compare the test results of the two methods.Results:A total of 53 cases of abnormal chromosomes were detected using CNV-seq combined with chromosome karyotyping technology, with an abnormal detection rate of 16.11%(53/329). Among them, 26 cases had consistent detection results, including 22 cases of aneuploidy, 2 cases of structural abnormalities and 2 cases of mosaic; CNV-seq detected 23 cases of chromosome copy number variations that were missed by karyotyping, including 17 cases of microdeletion and 6 cases of microduplication; chromosome karyotype analysis detected 4 cases of chromosome structural abnormalities that were missed by CNV-seq, including 3 cases balanced translocation and 1 case of inversion.Conclusions:CNV-seq has obvious advantages in detecting copy number variations of small fragments, which can make up for the lack of resolution of karyotyping analysis; CNV-seq combined with chromosome karyotyping analysis can improve the detection rate of abnormal chromosomes, which is important for prenatal diagnosis meaning.