Noonan syndrome and Noonan syndrome with multiple lentigines (formerly LEOPARD syndrome) as other RASopathies are autosomal dominant disorders caused by germline missense mutations of the Ras/mitogen-activated protein kinase (Ras/MAPK) signaling pathway; one of the phenotypic abnormalities is the development of HCM. This evidence concerns the gene WNK2 and Noonan syndrome with multiple lentigines.