PTPN11 and Noonan syndrome: Germline gain-of-function missense mutations in PTPN11 cause an overlapping but distinct group of dominant disorders with involvement of the face, heart, skeleton, skin, and brain, including Noonan syndrome (OMIM 163950), Noonan-like disorder with multiple giant cell lesion syndrome (OMIM 163955), and LEOPARD syndrome (OMIM 151100).