PTPN11 and Costello syndrome: This corroborates the finding that patient’s with Costello Syndrome (HRAS germline mutation) [39], Noonan Syndrome (NRAS, KRAS, PTPN11 germline mutations) [40] and Neurofibromatosis (NF1 germline mutation) [41] all have increased risk of developing fusion-negative RMS.