b'IGH Somatic Hypermutation Clonaltiy TestsClinical Information Test Name as well as for the definition of the extent of somatic hypermutation present in the IGH gene. Bioinformatics Lymphoid cells are different from the other somatic cellsImmunoglobulin variable heavy chain gene hypermutationIGH somatic hypermutation assaytools facilitate the characterization of sequences present in the body as during development, the antigen receptorstatus provides important prognostic information forIGHV leader assayat 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. During B-cell development, genes encoding the humansmall lymphocytic lymphoma (SLL). The presence of IGHAssay Type Bioinformatics also identify clonal rearrangements that immunoglobulin heavy chain (IGH) proteins are assembledSHM is defined as greater or equal to 2% difference frominvolve the V3-21 gene, which has been associated withfrom multiple polymorphic gene segments that undergothe germline VH gene sequence, whereas less than 2%Next-Generation Sequencing (NGS) a poor prognosis in CLL, independent of SHM status.rearrangements and selection, generating V H -D H -J H difference is considered evidence of no SHM. The status combinations that are unique in both length and sequenceof SHM for clone(s) has clinical relevance, as there is aThis test is performed by using the LymphoTrack or for each cell. 2-3An additional level of diversity is generatedclear distinction in the median survival of patients with andLymphoTrack Dx Assay from Invivoscribe. Indications for Testingby point mutations in the variable regions, also known aswithout SHM. Hypermutation of the IGH variable region dentify clonality in atypical lymphoproliferative Isomatic hypermutations (SHM).is strongly predictive of a good prognosis, while lack ofMethod Description disordersLeukemias and lymphomas originate from the malignantmutation predicts a poor prognosis. 4In addition, this assayFor detection of the vast majority of clonal IGH V H -J HSupport a differential diagnosis between reactive identifies clonal rearrangements involving the V3-21 gene, transformation of individual lymphoid cells, which meanswhich has been associated with a poor prognosis in CLLrearrangements, including the associated V H -J Hregion DNAlesions and hematologic malignanciesthat all leukemias and lymphomas generally share oneindependent of SHM status. This assay has been shown sequences, a multiplex master mix targeting the conservedAssign presumptive lineage in mature monoclonal or more cell-specific or clonal antigen receptor gene5 framework region 1 (FR1) or leader and the joining region rearrangements. Therefore, tests that detect IGH clonalto further stratify CLL patients. is used for PCR amplification. Next-generation sequencinglymphoproliferative disordersrearrangements can be useful in the study of B-cellof the PCR products is used to identify the frequencyMonitor and evaluate disease recurrencemalignancies.distribution of V Hregion and J Hregion segment utilization, Interpretation TurnaroundSpecimenShippingStorage Time Requirements Conditions ConditionsAn 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 the0.25-1 mL of bonefreeze (peripheralto testingrearrangement class for theblood or bone dominant clones and themarrow in Heparin,marrow) specific sequence for theEDTA or ACD500 ng of previouslyAmbient or dominant clone.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):837-845.28 LabPMM Services Catalog 2020|29'