Mutations in 16 genes, including PTPN11 (50%), SOS1 (20%) and RAF1 (5%–15%), have been linked to the development of Noonan syndrome (Kessler et al., 2021; Pagnamenta et al., 2019; Tartaglia et al., 2011; Wong et al., 2023). The gene discussed is PTPN11; the disease is Noonan syndrome.