The TFE3 Breakapart probe consists of two probes (279kb and 252kb), labelled in green, situated distal to the TFE3 gene and covering markers DXS6949 and STS-Z38762 and two probes (208kb and 325kb), labelled in red, situated proximal to the TFE3 gene and covering markers DXS9735 and DXS8366.
TFE3 (transcription factor binding to IGHM enhancer 3) is a protein-coding gene located at Xp11.23. Recurrent rearrangements of the TFE3 gene have been reported in a number of neoplastic diseases – often grouped together as ‘Xp11 translocation cancers’ – these include: renal cell carcinoma (RCC), soft tissue alveolar soft part sarcoma (ASPS), perivascular epithelioid cell tumors (PEComa), epithelioid hemangioendotheliomas (EHE) and melanotic Xp11 translocation renal cancer1,2.
In RCC, TFE3 translocation partners have been shown to include the ASPSCR1, SFPQ and NONO genes3. Although RCC and ASPS have been shown to have identical ASPSCR1-TFE3 fusion transcripts, the t(X;17) translocation is consistently balanced in the former but usually unbalanced in the latter - the derivative X chromosome is not seen in ASPS4.
In epithelioid hemangioendothelioma the novel YAP1-TFE3 fusion is seen, and defines a clinically distinct subset of this disease5,6, whereas in PEComa, the predominant partner has been shown to be the SFPQ gene7.
This research use only (RUO) probe has been designed for the investigation of TFE3 rearrangements, regardless of the partner gene involved.
We have successfully used CytoCell haematology probes over the last 5 years and were looking for the same quality and consistency for our FISH pathology screening. OGT worked closely with us to help our lab evaluate – and later validate – CytoCell pathology probes. CytoCell is now our primary FISH probe supplier. Results have been excellent and we were able to consolidate our workflow to follow a single, streamlined protocol.
Dr Mary Nordberg
Molecular Pathology Director, Delta Pathology Group, USA