Noonan syndrome, Costello, and other similar syndromes characterized by specific dysmorphic features and cardiac involvement with HCM development during infancy are caused by genetic mutations in a set of genes of the RAS-MAPK group (PTPN11, KRAS, SOS1, RAF1, SHP2) [100] (Figure 4). The gene discussed is PTPN11; the disease is Noonan syndrome.