Analysis of the sequencing results of whole genome chromosome copy number variation in isolated fetal pyelectasia

ObjectiveTo investigate the results of copy number variation sequencing(CNV-seq) and prognosis of isolated fetal pyelectasis.

MethodsThe interventional prenatal diagnosis was performed in 76 fetuses with isolated pyelectasia, and the data of chromosomal karyotypes and CNV-seq were retrospectively analyzed.The pregnancy outcomes were followed up.

ResultsThe analysis results of chromosomal karyotype in 76 fetuses with isolated pyelectasia showed that only 1 case was with D Down's syndrome, and 1 case was with chromosome 9 inversion.The results of CNV-seq analysis in 76 fetuses showed that only 1 case was with Down's syndrome, 2 cases were with polymorphic copy number variation(CNV), and no other CNV with pathogenicity, potential pathogenicity or unknown pathogenicity was found.Among 6 cases with pyelectasia, 51 cases were boys and 25 cases were girls.Two cases were induced labour, which included 1 case with Down's syndrome and 1 case with severe fetal hydronephrosis.In the remaining 74 live births, B-ultrasonography showed no exacerbation of pyelectasia or hydronephrosis.

ConclusionsThe vast majority of isolated fetal pyelectasia have a good prognosis, unless the pregnant woman is at high risk for Down's screening or noninvasive prenatal testing, and the routine prenatal CNV-seq analysis is not required.