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 t(14;20) translocation is one of seven recurrent IGH translocations that are referred to as primary oncogenic events in around 73% of Multiple Myeloma (MM) cases1.
These translocations result in a transcription product that dysregulates further genes, such as the cyclin family of cell cycle control genes, which then disrupts normal cell division. In the case of the t(14;20) translocation, 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 gene2. The resultant fusion and the up-regulated transcription product has been shown to cause dysregulation of Cyclin D2 in around 7% of tumours3. Of the seven translocation partners of IGH in multiple myeloma (including CCND1, CCND2, CCND3, MAF, MAFA and FGFR3/MMSET), MAFB has a prevalence of around 2%4. Involvement of any of the three MAF genes provides equally poor prognoses and a similar phenotype for patients5, but the MAFB translocation shows a different prevalence in multiple myeloma patients (2%) compared to Monoclonal Gammopathy of Undetermined Significance (MGUS) and Smoldering Multiple Myeloma (SMM) cases (7%)5.
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
1. Avet-Loiseau et al., Blood 2002;99(6):2185-91
2. Boersma-Vreugdenhil et al., Br J Haematol 2004;126:355-63
3. Bergsagel et al., Blood 2005;106(1):296-303
4. Zhan et al., Blood 2007;109(4):1692-700
5. Chng et al., Best Pract Res Clin Haematol 2007;20:571-96
- 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.