Prenatal diagnosis of chromosomal aberrations by chromosomal microarray analysis in fetuses with ultrasound anomalies in the urinary system

OBJECTIVES: This study aimed to explore the relationships between urinary anomalies and copy number variations (CNVs) in fetuses and provide information for prenatal diagnosis and genetic counseling for parents. METHODS: Three hundred seventeen fetuses with urinary system anomalies detected by prenatal ultrasound were enrolled; 251 had isolated urinary system anomalies, and 66 had nonisolated system anomalies. CMA was performed on the Affymetrix 750K platform. RESULTS: The frequency of chromosomal aberrations in fetuses with urinary system anomalies was 11.04%, including 6.31% with pathogenic CNVs (pCNVs). The detection rate of chromosomal abnormalities was significantly higher for the fetuses with nonisolated urinary system anomalies than for those with isolated urinary system anomalies. Seven fetuses (25.93%) with echogenic kidneys were identified with pCNVs; this detection rate was significantly higher than that for fetuses with other urinary anomalies. A 17q12 deletion was detected in eight fetuses with urinary anomalies, accounting for 40% of pCNVs. CONCLUSION: CMA is especially valuable in the prenatal diagnosis of fetuses with urinary system anomalies. The pCNV rates differed between the isolated and nonisolated subgroups of urinary anomalies. Fetuses with echogenic kidneys had the highest rate of pCNVs. The 17q12 deletion was the most frequent pCNV in fetuses with urinary anomalies.