Genomic imbalances in syndromic congenital heart disease

Abstract

Objective: To identify pathogenic genomic imbalances in patients presenting congenital heart disease (CHD) with extra cardiac anomalies and exclusion of 22q11.2 deletion syndrome (22q11.2 DS).

Methods: 78 patients negative for the 22q11.2 deletion, previously screened by fluorescence in situ hybridization (FISH) and/or multiplex ligation probe amplification (MLPA) were tested by chromosomal microarray analysis (CMA).

Results: Clinically significant copy number variations (CNVs ≥300kb) were identified in 10% (8/78) of cases. In addition, potentially relevant CNVs were detected in two cases (993kb duplication in 15q21.1 and 706kb duplication in 2p22.3). Genes inside the CNV regions found in this study, such as IRX4, BMPR1A, SORBS2, ID2, ROCK2, E2F6, GATA4, SOX7, SEMAD6D, FBN1, and LTPB1 are known to participate in cardiac development and could be candidate genes for CHD.

Conclusion: These data showed that patients presenting CHD with extra cardiac anomalies and exclusion of 22q11.2 DS should be investigated by CMA. The present study emphasizes the possible role of CNVs in CHD.

Keywords: 22q11 deletion syndrome; Aberrações cromossômicas; Cardiopatias congênitas; Chromosome aberrations; Comparative genomic hybridization; Congenital heart defects; DNA copy number variations; Hibridização genômica comparativa; Síndrome de deleção 22q11; Variações do número de cópias de DNA.