A rare mutation (p.Ala264Thr) of GATA4 is responsible for atrial septal defect and pulmonary valve stenosis.

Atrial septal defect (ASD) is a type of congenital heart defect characterized by the absence of atrial septal tissue. Research has shown that genetic factors play a significant role in the development of ASD. Variants in genes such as GATA binding protein 4 (GATA4), NK2 homeobox 5, and T-box transcription factor 5 have been identified in patients with ASD. In this study, we enrolled a Chinese family affected by ASD and PS. Whole exome sequencing and Sanger sequencing were used to investigate the genetic basis of lesions in this family. The AC16 cell line was used to perform the functional study. After data filtering and co-segregation analysis, we identified a rare mutation (NM_001308093.3: c.790G > A, p.Ala264Thr) in the GATA4 gene in the affected family members that was absent in the unaffected individuals. Bioinformatic analysis revealed that the newly identified mutation was deleterious and altered the hydrophobicity, size and polar of the GATA4 protein. Functional studies revealed that this rare mutation disrupted the stability of GATA4 and reduced the ability of GATA4 to activate the downstream target genes. Our findings highlight the importance of the N-terminal zinc finger structure of GATA4 in cardiac development. Additionally, our study contributes to the genetic diagnosis and counseling of families with congenital heart disease.