b'ClonalityIGH Somatic Hypermutation TestsClinical Information Test Name hypermutation present in the IGH gene. Bioinformatics Lymphoid cells are different from the other somatic cellsImmunoglobulin variable heavy chain gene hypermutationIGHV Leader Somatic Hypermutation Assay tools facilitate the characterization of sequences present in the body as during development, the antigen receptorstatus provides important prognostic information forat greater than 2.5% of the population and the level of genes in these cells undergo somatic gene rearrangement. 1 patients with chronic lymphocytic leukemia (CLL) andsomatic hypermutation present in the dominant clone. Assay Type Bioinformatics also identify clonal rearrangements that During B-cell development, genes encoding the humansmall lymphocytic lymphoma (SLL). The presence of IGHinvolve the V3-21 gene, which has been associated withimmunoglobulin heavy chain (IGH) proteins are assembledSHM is defined as greater or equal to 2% difference fromNext-Generation Sequencing (NGS) a poor prognosis in CLL, independent of SHM status.from multiple polymorphic gene segments that undergothe germline VH gene sequence, whereas less than 2% rearrangements and selection, generating V H -D H -J H difference is considered evidence of no SHM. The statusThis test is performed by using the LymphoTrack or combinations that are unique in both length and sequenceof SHM for clone(s) has clinical relevance, as there is aLymphoTrack Dx Assay from Invivoscribe. Indications for Testingfor each cell. 2-3An additional level of diversity is generatedclear distinction in the median survival of patients with and dentify clonality in atypical lymphoproliferative Iby point mutations in the variable regions, also known aswithout SHM. Hypermutation of the IGH variable regionMethod Description disorderssomatic hypermutations (SHM).is strongly predictive of a good prognosis, while lack of 4 For detection of the vast majority of clonal IGH V H -J HSupport a differential diagnosis between reactive mutation predicts a poor prognosis.In addition, this assay Leukemias and lymphomas originate from the malignantidentifies clonal rearrangements involving the V3-21 gene,rearrangements, including the associated V H -J Hregion DNAlesions and hematologic malignanciestransformation of individual lymphoid cells, which meanswhich has been associated with a poor prognosis in CLLsequences, a multiplex master mix targeting the conservedAssign presumptive lineage in mature monoclonal that all leukemias and lymphomas generally share oneframework region 1 (FR1) or leader and the joining region independent of SHM status. This assay has been shown lymphoproliferative disordersor more cell-specific or clonal antigen receptor geneto further stratify CLL patients. 5 is used for PCR amplification. Next-generation sequencing rearrangements. Therefore, tests that detect IGH clonalof the PCR products is used to identify the frequencyMonitor and evaluate disease recurrencerearrangements can be useful in the study of B-celldistribution of V Hregion and J Hregion segment utilization, malignancies.as well as for the definition of the extent of somatic Interpretation TurnaroundSpecimenShippingSpecimen Time Requirements Conditions StabilityAn interpretive report will be5 to 10 1-3 mL Peripheral BloodAmbient or2-8 C up issued indicating the levelbusiness daysin EDTA, ACD or Heparin Cool; do notto 7 days prior of IGH SHM along with thefreeze (peripheralto testingrearrangement class for the0.25-1 mL of boneblood or bone dominant clones and themarrow in Heparin,marrow) specific sequence for theEDTA or ACDdominant clone.500 ng of previouslyAmbient or References: isolated DNA frozen on dry ice (isolated DNA)1.Tonegawa S (1983). Somatic Generation of Antibody Diversity. Nature 302:575-581.2.Trainor KJ et al. (1990). Monoclonality in B-lymphoproliferative disorders detected at the DNA level. Blood 75:2220-2222.3.JE Miller et al., Molecular Genetic Pathology (2013, 2nd ed.) Springer Science & Business Media 302.2.7.13 and 30.2.7.18. 4.P. Ghia, et al. (2007). ERIC recommendations on IGHV gene mutational status in chronic lymphocytic leukemia. Leukemia 21:1-3. 5.Stamatopoulos, B et al. (2017). Targeted deep sequencing reveals clinically relevant subclonal IgHV rearrangements inchronic lymphocytic leukemia. Leukemia 31(4):837-845.26 LabPMM Services Catalog 2021|27'