CT genotype of TBX5 ‐rs6489957 was found in 12 ASD, 24 VSD, six PDA, three aortic coarctation and nine fallot that represent 42% of cases, while CC genotype present in 58% of the cases in contrast to 0.03% of control group (Table 6). Here, TBX5 is linked to atrial septal defect.