Prenatal diagnosis of 17q12 copy number variants in fetuses via chromosomal microarray analysis - A retrospective cohort study and literature review

Purpose: 17q12 copy number variants (CNVs) have variable presentations and incomplete penetrance, challenging prenatal counseling and management. This study aims to investigate the intrauterine phenotype. Methods: We included 48 fetuses diagnosed with 17q12 microdeletion or microduplication by chromosomal microarray analysis. Results: For 17q12 deletion, renal anomalies were found in 35 fetuses (35/37, 94.6 %), with hyperechogenic kidneys (HEK, 28/37, 75.7 %) and multicystic dysplastic kidneys (17/37, 45.9 %) being the most common findings. Duodenal obstruction (DO) was most frequently combined in 17q12 duplication fetuses. In addition, cardiac abnormalities were the first reported prenatal phenotype in 17q12 duplication fetuses. Conclusion: Our study shows that HEK and DO are the most predominant presentations of 17q12 deletion and duplication, respectively, and cardiac structural abnormalities may be associated with the latter. Although 17q12 CNVs have incomplete penetrance and variable expressivity and may be mainly involved in neurodevelopmental disorders, their short-term prognosis appears positive.