However, de novo deletions containing the NOTCH1 gene have only been described in patients with congenital heart defects such as tetralogy of Fallot (TOF), hypoplastic left heart syndrome (HLHS), and ventricular septal defect, but not in non-syndromic TAAs and tricuspid aortic valve (TAV). Here, NOTCH1 is linked to hypoplastic left heart syndrome.