b'IGH Clonality AssaysClinical InformationLymphoid cells are different from the other somatic cellsSince leukemia and lymphomas originate from the in the body as during development, the antigen receptormalignant transformation of individual lymphoid cells, genes of these cells undergo somatic gene rearrangement. 1 all leukemias and lymphomas generally share one or The human immunoglobulin heavy chain (IGH) gene locusmore cell-specific or clonal antigen receptor gene on chromosome 14 (14q32.3) includes 46-52 functionalrearrangements. Clonality does not always imply and 30 non-functional variable (V H ) gene segments, 27malignancy; all results must be interpreted in the context functional diversity (D H ) gene segments, and 6 functionalof all of the other available diagnostic criteria. Tests joining (J H ) gene segments spread over 1250 kilobases.that detect IGH clonal rearrangements are useful in the During B-cell development, genes encoding the IGHcharacterization, monitoring, and treatment of B- and molecules are assembled from multiple polymorphic geneT-cell malignancies.segments that undergo rearrangements and selection. These gene rearrangements of the variable, diversity and joining segments generate V H -D H -J Hcombinations of unique length and sequence for each cell. 2,3References1.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 30.2.7.18.24'