The risk factors that may affect the progression of monoclonal gammopathy of undetermined significance, often referred to as MGUS, include protein types and levels in the patient's blood, as well as the amount of time the patient has experienced MGUS, according to Mayo Clinic. However, doctors cannot accurately predict which patients are likely to develop serious related diseases such as cancer and blood disorders.
Patients with the greatest risk of MGUS progression are those with specific types of M protein in their blood, explains Mayo Clinic. The level of the M protein, as well as a free light chain protein in the blood, may also signal that a patient is more at risk for developing serious related diseases. Doctors closely monitor patients with MGUS so that if it progresses, they can treat them early.
MGUS develops when plasma cells in the blood produce an abnormal protein in the blood, reports Mayo Clinic. This M protein's presence in the blood usually causes no symptoms. But in some patients, an antibody can bind to nerves, leading to tingling, weakness or numbness, reports Merck Manual. Some patients may also experience fractures or bone loss.
The condition occurs in 5 percent of people over age 70, explains Merck Manual. In about 25 percent of patients, MGUS progresses to cancer.