<unk>  is caused by complete absence of the<unk>  valve. The underlying cause of this absence remains unknown. This prevents direct blood flow between the right atrium and the right ventricle. This causes the foramen ovale to remain open after birth, leading to atrial septal defect.
Tricuspid atresia
Double aortic arch
Interrupted aortic arch
Persistent truncus arteriosus
Double outlet right ventricle
Double inlet left ventricle
Situs ambiguus
Transposition of the great vessels