MG-128 Use of prenatal array comparative genomic hybridization in cases of fetal structural cardiac anomalies: New cases and review of the literature

Abstract

Background Array comparative genomic hybridization (aCGH) has been used to provide genome-wide screening for small chromosome imbalances in the prenatal setting, however use is not uniform across Canada. Many studies have looked at overall yield of aCGH, however, there has been less literature examining utility of array in the case of specific congenital anomalies. Objectives To determine the utility of aCGH in cases of prenatal cardiac anomalies. Methods A literature review was conducted using PubMed for all studies reporting results from prenatal aCGH, and those reporting cardiac anomalies as a distinct category were selected. Results of aCGH testing for cases prospectively recruited for this indication at our centre were also included. Outcome measures included detection rate, number of variants of uncertain significance (VOUS), and number of incidental findings. Results Eleven published studies and 22 patients at our centre were included. Most studies did not report cardiac anomaly-specific results for all categories of array results. Overall detection rate over karyotype for pathogenic anomalies was 6.6%. Incidental findings were found in 7.69% of cases. VOUS occurred in 1.47% of cases. Conclusions Array CGH increases the yield of chromosomal findings over karyotype alone in cases of prenatal cardiac anomalies, and has a place in clinical use. In addition, VOUS and incidental findings are as common as pathogenic anomalies in this cohort. Prenatal clinics must be prepared to deal with these findings in this setting. More studies are needed to determine the incidence of pathogenic, VOUS and incidental findings in cardiac-specific cases.