RASopathies are a group of autosomal dominant disorders caused by pathogenic variants in genes encoding proteins of the RAS/mitogen-activated protein kinase pathway, such as PTPN11. The clinical spectrum is characterized by specific facial features, congenital heart disease (CHD), and hypertrophic cardiomyopathy (HCM), and variable postnatal growth retardation, neurological involvement, and cancer predisposition [50]. The gene discussed is PTPN11; the disease is hypertrophic cardiomyopathy.