Molecular investigation of Ewing sarcoma: about detecting translocations

t(11;22)(q24;q12) FLI1-EWSR1 85 ETS t(21;22)(q22;q12) ERG-EWSR1 5–15 t(7;22)(p22;q12) ETV1-EWSR1 <1 t(17;22)(q12;q12) E1AF-EWSR1 <1 t(2;22)(q33;q12) FEV-EWSR1 <1 patients and characterized by adverse outcome. Recently our understanding of molecular pathogenesis of Ewing sarcoma has greatly progressed, and there have been some promising therapeutic advances. The cytogenetic hallmark of Ewing sarcoma is balanced translocation t(11;22)(q24;q12), first describedbyAurias et al (1983) and Turc-Carel et al (1983). The t(11;22)(q24;q12) was the first sarcoma associated translocation to be characterized at the molecular level. The translocation fuses the Ewing sarcoma breakpoint region 1 (EWSR1) in 22q12 with the Friend leukemia virus integration 1 (FLI1) gene in 11q24 to generate a novel hybrid gene. The EWSR1 gene encodes a multifunctional protein, member of the ten-eleven translocation (TET) family of proteins, that is involved in various cellular processes, including gene expression, cell signalling and ribonucleic acid (RNA) processing and transport. The protein encoded by FLI1 is a member of the E-twenty six (ETS) family of transcription factors that target deoxyribonucleic acid (DNA) sequences through structural motif in their DNAbinding region (Riggi et al, 2007). The t(11;22)(q24;q12) joins the 50portion of the EWSR1 gene to the DNA binding region of FLI1, thus resulting in