NOTCH1 and hypoplastic left heart syndrome: NOTCH1 (MIM# 190198) was the first gene associated with inherited aortic valve disease.5 Garg et al described two pedigrees, where predominantly left-sided, cardiac lesions (including BAV) co-segregated with damaging NOTCH1 mutations.5 Subsequently, NOTCH1 mutations were associated with other left (eg, CoA, hypoplastic left heart syndrome (HLHS)) and right-sided (eg, pulmonary stenosis, pulmonary atresia) congenital defects as well as tetralogy of Fallot (ToF) and Adams-Oliver syndrome (AOS).6–8