The EWSR1/ERG Translocation probe consists of green probes (215kb, 154kb) flanking the breakpoint region at the ERG gene locus and red probes (139kb, 151kb) flanking the breakpoint region at the EWSR1 locus.
Ewing's sarcoma (EWS) is the second most frequent primary bone cancer in patients under 20 years of age1. It is mainly characterised by a translocation between the two genes - EWSR1 (Ewing's Sarcoma Region 1) and FLI1 (Friend Leukaemia virus Integration 1) - in the t(11;22)(q24;q12) translocation, found in 83% of such tumours2. 10% of the remaining cases have a variant translocation involving EWSR1 and ERG, t(21;22)(q22;q12), and less than 1% carry one of the 7p22 (ETV1), 17q12 (E1AF) or 2q36 (FEV) translocations with EWSR13.
EWSR1 is also involved in translocations in desmoplasmic small round cell tumours, a subset of angiomatoid fibrous histocytomas, and possibly in myxoid liposarcoma4,5.
The EWSR1 breakapart probe can also be used to distinguish rare soft tissue sarcoma, a clear cell sarcoma, from malignant melanoma, a distinction that is difficult to make via either histology or immunohistology. The EWS-ATF1 (Activating Transcription Factor 1) translocation, t(12;22) (q13;q12), has been identified in 70-90% of clear cell sarcoma yet has not been observed in malignant melanoma6. This translocation can be detected using the EWSR1 breakapart probe. FISH has been shown to be a more sensitive and reliable method than RT-PCR for the diagnosis of EWS in solid tissues7.
The quality and reproducibility of results using the CytoCell kit has been vital in accurately detecting co-deletions in our glioma investigations. We now have a cost-effective test that we can rely on that is also easy to use and interpret. We've been consistently impressed with this kit - not to mention the support offered by OGT's customer service, and have completely transitioned over to CytoCell probes.
Gavin Cuthbert, FRCPath
Head of Cancer Cytogenetics, Northern Genetics Service, Newcastle, UK
