Aim
Outcomes after paediatric congenital heart disease (CHD) surgery vary widely even for the same lesion and repair. The aim of this Synergy study is to identify genetic hallmarks of unfavourable postoperative outcomes in CHD.
Methods
Children with CHD were classified as having unfavourable (n=267) or favourable (n=222) cardiovascular outcomes using our discovery cohort of NSW linked health data and underwent whole-exome sequencing. We performed rare-variant burden testing across 20,523 genes and 16,624 biological pathways, comparing unfavourable versus favourable groups. Significant signals were then interrogated in an independent Genomics England replication cohort (unfavourable n=232; favourable n=252) to assess replication.
Results
Unfavourable-outcome patients showed a higher burden of rare, deleterious variants in the bile acid gene SCL10A2, in a clotting factor XIII pathway, and in a TP53 cell cycle pathway. Intriguingly, favourable-outcome patients showed a higher burden of rare, deleterious variants in the cilia gene DNHD1.
Conclusion
Postoperative outcomes after CHD surgery are affected by genetic defects involved in bleeding and clotting, factors that are exacerbated by the cardiopulmonary bypass required for cardiac surgery. These findings require further validation, and suggest that actions will be possible to mitigate unfavourable outcomes resulting from defects in clotting-associated genes. Further genes also impact outcomes, and do not appear to be related to causal genetics of the underlying CHD disease.