Abstract

Background: Congenital Heart Disease (CHD) occurs in nearly 1% of newborns due to genetic and environmental factors. There are many genes involved in CHD. Variants of Gap Junction Protein Alpha 1 (GJA1), Zic Family Member 3 (ZIC3), Nodal Growth Differentiation Factor (NODAL), and Forkhead Box H1 (FOXH1) genes are common to develop CHD. Objectives: To date, no study has been published about CHD patients in Iran. Therefore, the present study aimed to evaluate the sequence variants of these genes in Iranian patients. Methods: This study was conducted on 73 patients with familial CHD and their family members. Genetic investigations were performed using Polymerase Chain Reaction (PCR) and direct DNA sequencing of the exons and flanking regions of the genes. The variants were evaluated using available online software tools. Mutation taster, PROVEAN, SIFT, PolyPhen-2, and CADD were used to predict the effects of the variants and I-TASSER was applied to evaluate the possible structural effects of the genetic variations. Results: c.612G \textgreater A, c.717G \textgreater A, and c.895C \textgreater T in GJA1 were found in the study participants. c.1248T \textgreater G in the ZIC3 was observed in a twin with CHD. Besides, c.193 + 12C \textgreater T, c.-109T \textgreater C, c.494A \textgreater G, c.417C \textgreater T, and c.357C \textgreater T variants were detected in the NODAL gene. Additionally, c.-314T \textgreater G, c.175-30C \textgreater T, and c.373A \textgreater T sequence changes were determined in the FOXH1 gene. Two novel heterozygous variants, namely c.1061C \textgreater G and c.-465C \textgreater A, were also found in the FOXH1 gene. Bioinformatics analysis indicated that the detected reported/novel variants might not have a damaging effect among Iranian CHD patients. Conclusion: The study results indicated the first variation screening of GJA1, ZIC3, NODAL, and FOXH1 genes in Iranian familial CHD patients. The results also suggested a minor role for GJA1, ZIC3, NODAL, and FOXH1 genes in familial CHD pathogenesis. However, their exact role in CHD causation entails further research.