Analysis of the phenotypic spectrum observed within the 28 affected pedigrees (harbouring pathogenic and likely pathogenic variants) revealed that in the majority NOTCH1 mutations were associated with a wide range of congenital heart diseases including complex lesions such as ToF, truncus arteriosus or HLHS (online supplemental table 1; no: 1, 7, 17, 19, 24, 41, 50). The gene discussed is NOTCH1; the disease is hypoplastic left heart syndrome.