The normal cell type most closely associated with MM cells is generally taken to be either an activated memory B cell or the precursor to plasma cells, the plasmablast.The immune system keeps the proliferation of B cells and the secretion of antibodies under tight control. When chromosomes and genes are damaged, often through rearrangement, this control is lost. Often, a promoter gene moves (or translocates) to a chromosome, where it stimulates an antibody gene to overproduction. A chromosomal translocation between the immunoglobulin heavy chain gene (on chromosome 14, locus q32) and an oncogene (often 11q13, 4p16.3, 6p21, 16q23 and 20q11) is frequently observed in people with multiple myeloma. This mutation results in dysregulation of the oncogene which is thought to be an important initiating event in the pathogenesis of myeloma. The result is a proliferation of a plasma cell clone and genomic instability that leads to further mutations and translocations. The chromosome 14 abnormality is observed in about 50% of all cases of myeloma. Deletion of (parts of) chromosome 13 is also observed in about 50% of cases. Production of cytokines (especially IL-6) by the plasma cells causes much of their localised damage, such as osteoporosis, and creates a microenvironment in which the malignant cells thrive. Angiogenesis (the generation of new blood vessels) is increased. The produced antibodies are deposited in various organs, leading to kidney failure, polyneuropathy, and various other myeloma-associated symptoms.
Among African Americans, myeloma is one of the top-10 causes of cancer death. UK
Myeloma is the 17th-most common cancer in the UK: around 4,800 people were diagnosed with the disease in 2011. It is the 16th-most common cause of cancer death: around 2,700 people died of it in 2012. Other animals
Multiple myeloma has been diagnosed in dogs, cats, and horses.In dogs, multiple myeloma accounts for around 8% of all haemopoietic tumors. Multiple myeloma occurs in older dogs and is not particularly associated with either males or females. No breeds appear overrepresented in case reviews that have been conducted. Diagnosis in dogs is usually delayed due to the initial nonspecificity and range of clinical signs possible. Diagnosis usually involves bone-marrow studies, X-rays, and plasma-protein studies. In dogs, protein studies usually reveal the monoclonal gammaglobulin elevation to be IgA or IgG in equal number of cases. In rare cases the globulin elevation is IgM, which is referred to as Waldenströms macroglobulinemia. The prognosis for initial control and return to good quality of life in dogs is good;  43% of dogs started on a combination chemotherapeutic protocol achieved complete remission. Long-term survival is normal, with a median of 540 days reported. The disease eventually recurs, becoming resistant to available therapies. The complications of kidney failure, sepsis, or pain can lead to an animals death, frequently by euthanasia. See also
References
External links

Multiple myeloma at Curlie