The Ewing sarcoma family of tumors (primitive neuroectodermal tumors; PNET) comprise morphologically heterogeneous tumors that are characterized by nonrandom chromosomal translocations involving the EWS gene on chromosome 22q12 and one of several members of the ETS family of transcription factors. The tumors include Ewing sarcoma, peripheral neuroepithelioma, and Askin tumor. In approximately 90% of cases of ESFT, the FLI1 gene (193067) on chromosome 11 is the fusion partner of EWS; in approximately 10%, the EWS fusion partner is the ERG gene (165080) on chromosome 22. Many other ETS family members have been identified as fusion partners of EWS, but these cases are rare (Khoury, 2005). [from
OMIM]