XL t(14;20) IGH/MAFB DF consists of a green-labeled probe hybridizing to the IGH gene region at 14q32.3 and an orange-labeled probe hybridizing proximal to the MAFB gene region 20q12.

Probe maps are created in accordance with the intended purpose of the product. Solid colored bars do not necessarily indicate that the probe fully covers the indicated genomic region. Therefore, caution is advised when interpreting results generated through off-label use. Probe map details based on UCSC Genome Browser GRCh37/hg19. Map components not to scale. Further information is available on request.

The most frequent primary abnormalities in multiple myeloma (MM) are trisomies of odd-numbered chromosomes or translocations involving the immunglobulin heavy chain (IGH) gene locus. The most common MM-associated IGH translocations are t(11;14), t(4;14), t(6;14), t(14;16) and t(14;20) in the order of their occurrence. The consequence of these rearrangements is the dysregulation of genes juxtaposed to transcriptional enhancers in the IGH locus. Prognosis and risk stratification strongly depends on the detection and interpretation of cytogenetic primary abnormalities. t(14;16) and t(14;20) are considered as high risk, t(4;14) as intermediate risk, and t(6;14) and t(11;14) as standard risk cytogenetic aberrations in patients with MM based on FISH testing. Secondary aberrations are also influencing the outcome.
Even if associated with poor prognosis in MM, monoclonal gammopathy of undetermined significance/smoldering multiple myeloma (MGUS/SMM) cases characterized by t(14;20) can be stable for years before progression occurs, whereas MGUS/SMM cases with t(4;14) and t(14;16) are showing a higher progression rate. The recurrent t(14;20) results in ectopic expression of the basic leucine zipper transcription factor MAFB which has an important role in lineage-specific hematopoiesis.

Clinical Applications

• Multiple Myeloma and Plasma Cell Neoplasms (MM)

XL t(14;20) IGH/MAFB DF hybridized to lymphocytes. Two normal interphases are shown.

• Boersma-Vreugdenhil et al (2004) Brit J Haem 126:355-363
• Ross et al (2010) Haematologica 95:1221-1225
• Rajan and Rajkumar (2015) Blood Cancer J 5:e365

• Utility and performance of bacterial artificial chromosomes-on-beads assays in chromosome analysis of clinical prenatal samples, products of conception and blood samples.
• A child with multiple congenital anomalies due to partial trisomy 7q22.1 → qter resulting from a maternally inherited balanced translocation: a case report and review of literature.
• Distinct roles of ATM and ATR in the regulation of ARP8 phosphorylation to prevent chromosome translocations.
• Heterogeneous MYCN amplification in neuroblastoma: a SIOP Europe Neuroblastoma Study.
• Immense random colocalization, revealed by automated high content image cytometry, seriously questions FISH as gold standard for detecting EML4-ALK fusion.
• Fluorescence in situ hybridisation assays designed for del(7q) detection uncover more complex rearrangements in myeloid leukaemia cell lines
• Detection of t(7;12)(q36;p13) in paediatric leukaemia using dual colour fluorescence in situ hybridisation.
• A rare case of t(11;22) in a mantle cell lymphoma like B-cell neoplasiaresulting in a fusion of IGL and CCND1: case report.
• Genomic DNA-chip hybridization in t(11;14)-positive mantle cell lymphomas shows a high frequency of aberrations and allows a refined characterization of consensus regions.