TLL1 and GATA6 have been identified as pathogenic mutations in sporadic ASD4, 5, while NKX2.5, GATA4, TBX20, MYH6, and TBX5 contribute to ASD in families with autosomal dominant inheritance6, 7, 8, 9, 10. Here, TBX20 is linked to atrial septal defect.