XL IRF4 BA consists of a green-labeled probe hybridizing proximal to the IRF4 gene region at 6p25 and an orange-labeled probe hybridizing distal to the IRF4 gene region at 6p25.

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 updated (2016) revision of the World Health Organization (WHO) classification of tumors of lymphoid neoplasms considers the large B-cell lymphoma with IRF4 rearrangement as a new provisional entity. Head and neck regions including the Waldeyer ring are particularly affected. Chromosomal translocations involving the IRF4 gene and the immunoglobulin loci IGH, IGL and IGK (IG) result in dysregulation of IRF4 expression; other translocation partners may occur. Since t(6;14)(p25;q32) is cytogenetically cryptic, FISH is a valuable tool in detecting this recurrent aberration. IG/IRF4 positive lymphomas normally lack t(14;18), which is observed in about 85% of adult patients with follicular lymphoma, and are commonly associated with young age and a good course. IRF4 rearrangements have also been identified in peripheral T-cell lymphomas (PTCL). PTCL are defined as a diverse group of aggressive lymphomas of mature-stage T-cells accounting for about 10% of non-Hodgkin lymphomas. Recent data suggests that IRF4 translocations detected by FISH have a predictive value for primary cutaneous CD30(+) anaplastic large cell lymphoma.

Clinical Applications

• Non-Hodgkin Lymphomas (NHL)

XL IRF4 BA hybridized to lymphozytes. One aberrant cell with split signal is shown, indicating a break in the IRF4 locus. Additionally, one normal interphase is shown.

• Feldman et al (2009) Leukemia 23:574-580
• Salaverria et al (2011) Blood 7:139-147
• Kiran et al (2013) Leukemia Research 37:396-400