b'TRG Clonality AssayClinical InformationThe human T-Cell Receptor Gamma (TRG) locus onSince leukemias and lymphomas originate from the chromosome 7 (7q14) includes 14 variable (V) genesmalignant transformation of individual lymphoid cells, (Group I, II, III, and IV), 5 joining (J) gene segments, and which means that all leukemias and lymphomas generally 2 constant (C) genes spread over 200 kilobases. 1 share one or more cell-specific or clonal antigen Lymphoid cells are different from the other somatic cellsreceptor gene rearrangements. Clonality does not always in the body, as during development the antigen receptorimply malignancy; all results must be interpreted in the genes in lymphoid cells (including gene segments withincontext of all of the other available diagnostic criteria. the TRG locus), undergo somatic gene rearrangement. 2 Tests that detect TRG clonal rearrangements can be used These developmentally regulated, programmed geneto help identify T-cell and certain B-cell malignancies. rearrangements generate V-J combinations that are unique for each cell. 3Note: During T-cell ontogeny, rearrangement of the TRG locus occurs before rearrangement of the alpha beta loci.Therefore, clonal rearrangements of TRG are often present, commonly detected, and can be tracked in T-cell malignancies involving alpha-beta T-cells. This makes TRG a powerful tool for both clonal and MRD analysis of T-cell and some B-cell tumors.References1.LC Lawnickie, et al. (2003). The distribution of gene segments in T-cell receptor gamma gene rearrangements demonstratesthe need for multiple primer sets. J Mol Diagn. 5:82-87.2. Tonegawa S (1983) Somatic Generation of Antibody Diversity. Nature 302:575-581.3.JE Miller et al., Molecular Genetic Pathology (2013, 2nd ed.) Springer Science & Business Media 302.2.7.13 and 30.2.7.18.32'