What's monoclonal gammopathy of undetermined significance?

MGUS. Is a common precancerous condition affecting people 50 years of age and older. It was first described by mayo clinic researchers in 1978 and is characterized by the presence of an abnormal protein in the blood called a (monoclonal) protein or m protein.Mgus has a small risk (1 percent each year) of progressing to a blood cancer called multiple myeloma or a related condition.