CTNNA1 and familial atrioventricular septal defect: For the construction of the risk signature model, the LASSO analysis was applied for ECD-associated genes and 11 hub genes, namely ATG5, ATG7, BECN1, CDC42, CDH1, CTNNA1, CYBB, MYH14, RHOA, RNF146, and UVRAG (Fig. 2A and B).