The application of chromosomal microarray analysis to the prenatal diagnosis of isolated mild ventriculomegaly.

Objective: To investigate the clinical value of chromosomal microarray analysis (CMA) in the prenatal diagnosis of genetic abnormalities in fetal isolated mild ventriculomegaly.

Materials And Methods: This retrospective study reviewed 101 fetuses with isolated mild ventriculomegaly who had undergone invasive prenatal diagnosis at our hospital. CMA was performed in all cases to detect chromosomal aneuploidy as well as copy number variations (CNVs) that are too small to be detected by conventional karyotyping. Real time quantitative PCR (qPCR) or multiplex ligation dependent probe amplification (MLPA) was used to confirm all fetal CNVs <400 Kb.

Results: Except for three cases of chromosomal aneuploidy, CMA revealed pathogenic copy number variations (CNVs) in 3.0% (3/101) of the fetuses; these cases demonstrated involvement in the chromosomal regions 15q11.2, 1q21.1 and Xq27.3q28. Furthermore, we detected three likely pathogenic (3.0%) and two variants of uncertain significance (2.0%) among 101 fetuses diagnosed as isolated mild ventriculomegaly on ultrasound examination.

Conclusion: Our study suggests that CNVs could aid in the risk assessment and genetic counseling in fetuses with isolated ventriculomegaly.