The origin and formation of chromosomal translocations in multiple myeloma

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Klin Onkol 2008; 21(2): 53-58.

Multiple myeloma is a malignant disease of terminal developmental stages of B-lymphocytes, i.e. plasma cells. During the progress of the disease genetic changes are cumulated in these cells which are the cause of their fully malignant phenotype. The affection of plasma cells is characterized by the presence of various numerical and structural chromosomal aberrations. A frequent cytogenetic fi nding is the presence of reciprocal translocations originating within the process of the so-called illegitimate switch recombination, affecting the gene for heavy chains of immunoglobulins (IgH) in the 14q32 chromosome area. As a result of this recombination the oncogenes on derived chromosomes
get under control of the molecular enhancers of the IgH locus. This paper summarizes the current knowledge concerning the formation mechanism of chromosomal translocations in multiple myeloma and the areas of their formation; it also mentions the way of their detection. The paper presents the most frequent types of chromosomal translocations affecting the area of chromosome 14q32 in the karyotype of people diseased with multiple myeloma, including the frequency of their detection and the prognostic signifi cance for the patients.