E2A/PBX1 Translocation, Dual Fusion
- E2A, 19p13.3, Green
- PBX1, 1q23.3, Red
The E2A probe, labelled in green, contains two probes (110kb and 146kb) that cover the 3’ end of the E2A (TCF3) gene and flanking region and a 321kb probe that covers a region 5’ (centromeric) to the gene. The PBX1 probe, labelled in red, contains two probes (147kb and 110kb) that map within the PBX1 gene and a 117kb probe that maps 3’ (telomeric) to the gene.
The TCF3 (transcription factor 3) gene is located at 19p13.3 and PBX1 (PBX homeobox 1) at 1q23.3. Translocations involving TCF3 are some of the most common rearrangements in childhood B-cell acute lymphoblastic leukaemia (ALL)1,2.
Two of the main TCF3 partners are PBX1 at 1q23.3 and HLF at 17q22. These become fused to TCF3 as a result of the t(1;19)(q23;p13) and t(17;19)(q22;p13) translocations, forming the TCF3-PBX1 and TCF3-HLF fusion genes, respectively. A rare cryptic inversion, inv(19)(p13;q13), has been reported to fuse TCF3 to TFPT (TCF3 fusion partner), resulting in the TCF3-TFPT fusion gene1.
UK and European best practice guidelines suggest that when a TCF3 rearrangement is identified in B-cell ALL, it is important to distinguish between t(17;19)(q22;p13) and t(1;19)(q23;p13) as the former translocation is associated with adverse prognosis3,4.
In our hands, Cytocell FISH probes, have proven to be of the highest quality with bright, easy to interpret signals, thus providing confidence in our results. Cytocell’s customer support is outstanding, as their staff are extremely knowledgeable and truly care about their customers and their customers’ needs. Jennie Thurston, Director of Cytogenetics at Carolinas Pathology Group
- Van der Burg et al., Leukemia 2004;18(5):895-908
- Swerdlow et al., (eds,) WHO Classification of Tumours of Haematopoietic and Lymphoid Tissue, Lyon, France, 4th edition, IARC,2017
- Professional Guidelines for Clinical Cytogenetics: Acute Lymphoblastic Leukaemia BEST PRACTICE GUIDELINES (2011) V1.00. www.cytogenetics.org.uk
- Hasting et al., Guidelines and Quality Assurance for Acquired Cytogenetics (2013) ECA Newsletter:31
- Arsham, MS., Barch, MJ. and Lawce HJ. (eds.) (2017) The AGT Cytogenetics Laboratory Manual. New Jersey: John Wiley & Sons Inc.
- Mascarello JT, Hirsch B, Kearney HM, et al. Section E9 of the American College of Medical Genetics technical standards and guidelines: fluorescence in situ hybridization. Genet Med. 2011;13(7):667-675.
- Wiktor AE, Dyke DLV, Stupca PJ, Ketterling RP, Thorland EC, Shearer BM, Fink SR, Stockero KJ, Majorowicz JR, Dewald GW. Preclinical validation of fluorescence in situ hybridization assays for clinical practice. Genetics in Medicine. 2006;8(1):16–23.
- Area of Interest*
This product is intended to be used on Carnoy’s solution (3:1 methanol/acetic acid) fixed haematological samples.
*Disease information supported by the literature and is not a reflection of the intended purpose of this product.