New publication in the European Heart Journal

In this publication, researchers used Swedish register data to examine how congenital heart defects (CHD) cluster within families across different kinships and generations. The study revealed clear dose-response patterns, with CHD risk increasing based on the number of affected relatives. Recurrence patterns varied by kinship type and genetic relatedness, with the strongest associations found among mothers, full siblings, and offspring, while more modest associations appeared for fathers and half-siblings. These findings suggest both genetic and potential maternal-specific mechanisms play roles in familial CHD.

Sara, one of the researchers, highlighted that the most compelling aspect was studying familial aggregation at such scale and detail. By linking nationwide health registers with the Swedish Multi-Generation Register, the team examined CHD across different relative types, generations, and numbers of affected family members. The Swedish Multi-Generation Register links individuals born in Sweden to their biological parents and, through them, to siblings, half-siblings, and offspring; this near-complete population coverage over several decades minimises selection bias and allows construction of large family networks spanning multiple generations.

The key takeaway demonstrates that congenital heart defects cluster systematically within families, with likelihood increasing through both the number of affected relatives and the degree of genetic relatedness. The findings underscore the importance of detailed family history and maternal health when assessing familial CHD risk.