Loss-of-function mutations in TBX20 are associated with atrial septal defects (ASDs), valve disease, cardiomyopathy and Tetralogy of Fallot (i.e. pulmonary outflow tract obstruction, ventricular septal defect and overriding aortic root) (Huang et al., 2017; Liu et al., 2008; Monroy-Muñoz et al., 2015; Qian et al., 2008; Zhao et al., 2016). This evidence concerns the gene TBX20 and Abnormal cardiac septum morphology.