While the somatic variants in KRAS, NRAS, PTPN1, NF1 (Neurofibromin 1), and CBL involved in RAS/MAPK pathway are frequent in different types of cancers, germline variants in these genes are associated with a diverse group of congenital disorders (neurofibromatosis type 1, cardiofaciocutaneous syndrome, Costello syndrome, Noonan syndrome, and Noonan syndrome with multiple lentigines), often referred to as ‘RASopathies’. The gene discussed is NF1; the disease is Noonan syndrome with multiple lentigines.