SHP2, which is encoded by PTPN11, is a ubiquitously expressed PTPase that plays an essential role in the development and/or maintenance of multiple organs and tissues.34 Mutations in PTPN11 are associated with human Noonan syndrome,35,36 Leopard syndrome,37 and metachondromatosis (MC),38–41 all of which have severe skeletal manifestations. The gene discussed is PTPN11; the disease is metachondromatosis.