Lymphomas

Identification of gene rearrangements and clonality analysis are important techniques for the diagnosis of malignant lymphoproliferative diseases. Malignant tumor cells exhibit clonality, whereas reactive cells (benign) show polyclonality. Most B cell lymphomas reveal clonal IG gene rearrangements, and T cell lymphomas show clonal TCR gene rearrangements. PCR-based detection of rearranged immunoglobulin heavy chain genes can be used as an aid to establish a diagnosis of a B-cell lymphoma. Likewise, analysis of T cell receptor (TCR) gene rearrangements is an important tool for the diagnosis of T cell non-Hodgkin lymphomas (NHL). In particular the T cell receptor γ gene (TCRγ) has been the preferential target for clonality analysis for a long time due to its restricted germline repertoire, containing nine functional variable (V) region genes and five joining genes.