Interpretation Turn-around Time Specimen Requirements Shipping Conditions Storage Conditions  An interpretive report will be issued indicating whether evidence of clonality was detected. The report further provides a summary of the top 5 merged sequences, including the % total reads, the rearrangement class and the sequence. 5 to 10 business days •  3 mL of peripheral blood in Heparin, EDTA or ACD •  1 mL of bone marrow in Heparin, EDTA or ACD •  500 ng of previously isolated DNA • FFPE tissue samples Ambient or Cool; Do not freeze • Room Temp up to 72 hours •  2-8 °C up to 7 days Test Name TRG clonality assay Assay Type Next-Generation Sequencing (NGS) This test is performed by using the LymphoTrack® Assay from Invivoscribe. Method Description For detection of the vast majority of TRG gene rearrangements, a multiplex master mix targeting the Vγ and Jγ regions are used for PCR amplification. Next-generation sequencing of the PCR products is used to identify DNA sequences specific to clonal gene rearrangements. Bioinformatics tools facilitate the characterization of sequences present at greater than 2.5% or 5% of the population. These sequences can be used to track specific clonal populations. Indications for Testing •  Identify clonality in atypical lymphoproliferative disorders •  Support a differential diagnosis between reactive lesions and hematologic malignancies •  Assign presumptive lineage in mature monoclonal lymphoproliferative disorders • Monitor and evaluate disease recurrence Clonaltiy Tests LabPMM Services Catalog 2019 | 39 Clinical Information The human T-Cell Receptor Gamma (TRG) locus on chromosome 7 (7q14) includes 14 variable (Vγ) genes (Group I, II, III, and IV), 5 joining (Jγ) gene segments, and 2 constant (Cγ) genes spread over 200 kilobases1 . Lymphoid cells are different from the other somatic cells in the body, as during development the antigen receptor genes in lymphoid cells (including gene segments within the TRG locus), undergo somatic gene rearrangement2 . These developmentally regulated, programmed gene rearrangements generate Vγ-Jγ combinations that are unique for each cell3 . Leukemias and lymphomas originate from the malignant transformation of individual lymphoid cells, which means that all leukemias and lymphomas generally share one or more cell-specific or “clonal” antigen receptor gene rearrangements. Clonality does not always imply malignancy; all results must be interpreted in the context of all of the other available diagnostic criteria. Tests that detect TRG clonal rearrangements can be used to help identify T-cell and certain B-cell malignancies. TRG Clonality Assay References 1.  LC Lawnickie, et al. (2003). The distribution of gene segments in T-cell receptor gamma gene rearrangements demonstrates the 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. Note: 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 38