Implications of monogenic bicuspid aortic valve (BAV) forms among sporadic BAV patients

Bicuspid aortic valve (BAV) represents the most common congenital heart defect and is genetically heterogeneous. While the majority of cases results from common risk variants that confer disease cumulatively, a small proportion of BAV cases has a monogenic etiology where penetrant rare variants (RVs) in single genes are disease causing. We assessed the proportion of monogenic BAV cases in 740 non-syndromic and non-familial BAV patients that should be representative for cardiovascular centers of maximum care. We used next generation sequencing- (NGS-) based single-molecule molecular inversion probes (smMIPs) and analyzed all monogenic BAV genes that have been identified so far (NOTCH1, SMAD6, ROBO4, GATA4, GATA6, and ADAMTS19). In these genes, we identified potential damaging RVs in 2% of our patients, which were not significantly enriched compared to 726 population-based controls. We conclude that the contribution of monogenic BAV forms is only small among non-syndromic and sporadic BAV patients.