The IGH/MALT1 product consists of probes, labelled in green, covering the Constant, J, D and Variable segments of the IGH gene, and MALT1 probes, labelled in red. The MALT1 probe mix contains four probes, two 171kb, 228kb probes positioned centromeric to the MALT1 gene and two 132kb, 306kb probes positioned telomeric to the MALT1 gene.
The t(14;18)(q32;q21) involving the Immunoglobulin heavy chain locus (IGH) at 14q32 and the Mucosa Associated Lymphoid Tissue Lymphoma Translocation gene 1 (MALT1) at 18q21 is a recurrent abnormality in MALT lymphoma1.
Extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue is listed as a distinct clinicopathologic entity. MALT lymphomas comprise 7.6% of all non-Hodgkin lymphoma's (NHLs) and represents 1 of the 6 most common NHLs2. MALT lymphomas are characterised by a proliferation of neoplastic marginal zone-related cells that invade the epithelial structures to generate lymphoepithelial lesions and colonise reactive lymphoid follicles3. t(14;18)/IGH-MALT1- positive MALT lymphomas originate in sites such as the liver, skin, ocular adnexa, or salivary glands1. The molecular characteristics of the t(14;18) resemble those found in the t(14;18)/IGH-BCL2 (follicular lymphoma) and t(11;14)/MALT1-IGH (mantle cell lymphoma), suggesting that these translocations could be generated by common pathomechanisms involving illegitimate V(D)J-mediated recombination of IGH as well as non-homologous end joining (NHEJ) or alternative NHEJ repair pathways1.