ZytoLight ® SPEC EWSR1/FLI1 TriCheckTM Probe

 The ZytoLight ® SPEC EWSR1/FLI1 TriCheck™ Probe is designed to detect translocations involving the chromosomal region 22q12.2 harboring the EWSR1 (Ewing sarcoma breakpoint region 1, a.k.a. EWS) gene and the chromosomal region 11q24.3 harboring the FLI1 (Fli-1 protooncogene, ETS transcription factor, a.k.a. EWSR2) gene. Translocations involving the chromosomal region 22q12.2 are found in 90-95% of patients with Ewing sarcoma or peripheral primitive neuroectodermal tumors (PNET). Ewing sarcoma is the second most common, highly malignant bone tumor in children and young adults. The most frequent translocation involving the EWSR1 gene region is t(11;22)(q24.3;q12.2) juxtaposing the EWSR1 gene in 22q12.2 next to the FLI1 locus. FLI1 is a member of the ETS family of transcription factors. Less frequently, EWSR1 can also be fused to ERG, a transcription factor closely related to FLI1 but located in 21q22.2. For prognosis and appropriate treatment it is important to differentiate Ewing sarcoma/PNET from classic neuroblastoma, Wilms tumor, and rhabdomyosarcoma. In combination with the histopathological diagnosis, detection of the EWSR1 rearrangements by FISH can be used to confirm the diagnosis of Ewing sarcoma/PNET.