IGH/MAFB Plus Translocation, Dual Fusion
- MAFB, 20q12, Red
- IGH, 14q32.33, Green
The IGH/MAFB Plus product consists of probes, labelled in green, proximal to the Constant, and within the Variable segment of the IGH region and MAFB probes (195kb, 161kb and 401kb), labelled in red. The MAFB probes are located on either side of the breakpoint region (between MAFB and PPP1R16B).
The MAFB (MAF bZIP transcription factor B) gene is located at 20q12 and IGH (immunoglobulin heavy locus) at 14q32.33.
Approximately 50-60% of multiple myeloma (MM) cases are associated with translocations involving IGH and one of several partners including CCND1, NSD2 (MMSET) and FGFR3, CCND3, MAF or MAFB1.
The t(14;20)(14q32;q12) translocation is a recurrent translocation seen in around 2% of MMs2,3.
The reciprocal rearrangement brings a truncated form of the IGH μ-enhancer (Eμ, located between the joining (J) segments and the constant region of the IGH gene) in close contact with the MAFB gene4. The resultant fusion and the up-regulated transcription product has been shown to cause dysregulation of cyclin D21.
The prognostic outcome of t(14;20)(14q32;q12) is assumed to be the same as the t(14;16)(q32;q23)3.
I first came across Cytocell FISH probes in a previous lab I worked in and I was struck by the quality of the products. Since this time, I have been recommending and introducing Cytocell probes across all application areas — now they are the primary FISH probes used in our lab. They have an excellent range of products and their ready-to-use reagent format saves considerable time. As a matter of fact, at a recent conference there was a discussion about the lack of commercial probes for a particular disorder and I was happy to point the participants in the direction of the Cytocell catalogue, which contains the exact probes required. Elizabeth Benner, Medical Technologist at the University of Arizona Health Network
- Fonseca et al., Cancer Research 2004;64:1546-1558
- Fonseca et al., Leukemia 2009;23(12):2210-2221
- Sawyer, Cancer Genetics 2011;204(1):3-12
- Boersma-Vreugdenhil et al., Br J Haematol 2004;126:355-63
- 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.