Consistent findings have been obtained in studies where gain-of-function Tbx20 mutations lead to a diverse array of cardiac defects, including abnormal ventricular walls, double outlet right ventricle (DORV), congenital atrial septal defects, patent foramen ovale (PFO), bicuspid aortic valve (BAV), and typical symptoms presented in familial tetralogy of Fallot (Posch et al., 2010; Zhang et al., 2011; Pan et al., 2015; Huang et al., 2017; Luyckx et al., 2019). This evidence concerns the gene TBX20 and Patent foramen ovale.