Prenatal Array Comparative Genomic Hybridization in Fetuses With Structural Cardiac Anomalies.

Abstract

To examine the diagnostic performance of array comparative genomic hybridization (CGH) for fetal cardiac anomalies in two medium-sized Canadian prenatal genetics clinics. We prospectively recruited 22 pregnant women with fetal structural cardiac anomalies, normal rapid aneuploidy detection, and FISH for 22q11.2 testing for array CGH analysis. One case had an 8p deletion that was also visible on karyotype and included the GATA4 gene, which has been associated with congenital heart disease. Two cases had inherited pathogenic copy number variants (CNVs) of variable expressivity and penetrance: one was a duplication of 16p11.2 and the other a deletion of 15q11.2. One case had the incidental finding of being a carrier of a recessive disease unrelated to the cardiac anomaly. Of these prospectively recruited cases of fetal cardiac anomalies, 14% had a pathogenic result on array CGH. Pathogenic CNVs of variable penetrance and expressivity were a significant proportion of the positive results identified. These CNVs are generally associated with neurodevelopmental issues and may or may not have been associated with the fetus' underlying congenital heart disease. Array CGH increases the diagnostic yield in this group of patients; however, certain CNVs remain a challenge for counselling in the prenatal setting.