Monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance
Other names	Benign monoclonal gammopathy, monoclonal gammopathy of unknown significance, monoclonal gammopathy of renal significance,[1] unknown or uncertain may be substituted for undetermined
Schematic representation of a normal protein electrophoresis gel. A small spike would be present in the gamma (γ) band in MGUS

Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell dyscrasia in which plasma cells or other types of antibody-producing cells secrete a myeloma protein, i.e. an abnormal antibody, into the blood; this abnormal protein is usually found during standard laboratory blood or urine tests. MGUS resembles multiple myeloma and similar diseases, but the levels of antibodies are lower,^[2] the number of plasma cells (white blood cells that secrete antibodies) in the bone marrow is lower, and it rarely has symptoms or major problems. However, since MGUS can lead to multiple myeloma, which develops at the rate of about 1.5% a year, or other symptomatic conditions, yearly monitoring is recommended.

The progression from MGUS to multiple myeloma usually involves several steps. In rare cases, it may also be related with a slowly progressive symmetric distal sensorimotor neuropathy.^[3]