MGUS or monoclonal gammopathy of undetermined significance is a state in which there is an atypical protein known as M protein or paraprotein present in the blood. This protein is made in the plasma cells of the bone marrow.


What Causes You To Have MGUS Or Monoclonal Gammopathy Of Undetermined Significance?

The exact cause of MGUS or monoclonal gammopathy of undetermined significance is not known. It is speculated that certain genetic changes and some environmental influences may be the triggers for this condition.

As is known, MGUS happens when abnormal but non-cancerous plasma cells make a protein called M protein or paraprotein or monoclonal protein. This protein is usually not harmful for many people. However, if a large quantity of this protein collects, it may crowd out the healthy cells present in the bone marrow and can lead to a damage of other cells in the body.

Risk Factors For Monoclonal Gammopathy Of Undetermined Significance

There are certain factors that may increase your chances of getting MGUS-

Age- The mean age found at the time of diagnosis is around 70 years

Sex- Men are more commonly seen to be affected by monoclonal gammopathy of undetermined significance


Race- People belonging to African and African-American race are more prone to getting this disorder than white people. For other races, the incidence is not clear

History- If members of your family have MGUS; you may be at an increased chance of getting affected by this condition


Complications Of Monoclonal Gammopathy Of Undetermined Significance

A small number of people may get a few complications and may progress in the disease to develop other serious condition. The conditions that may develop usually depend upon the kind of MGUS that one is suffering from. The types of MGUS and the complications related to them are –

Non- IgM MGUS-

This is the commonest kind of monoclonal gammopathy of undetermined significance and possesses a grave risk of progressing into multiple myeloma. Uncommonly, it can lead to some other more serious disorders


This type can lead to a rare form of cancer known as Waldenstrom macroglobulinemia. Less commonly it can lead to lymphoma, multiple myeloma or amyloidosis

Light chain MGUS-

This is a new type added to the classification and this can lead to a disorder in which the m protein is present in the urine. This is known as Bence Jones proteinuria

The progress of MGUS to these conditions will depend on may factors like-

  • The kind and size of monoclonal proteins in the blood
  • The quantities of a different small protein known as free light chain in the blood
  • The age of the person at the time of being diagnosed with monoclonal gammopathy of undetermined significance. The longer the time you have been suffering from
  • MGUS, the greater is the risk of getting more serious disorders

Symptoms Monoclonal Gammopathy Of Undetermined Significance

MGUS usually does not produce any signs or symptoms. However, a small number of people may experience symptoms, which may include-

  • Rash or nerve problems
  • Numbness or tingling
  • Problems with balancing, because nerves get damaged due to the paraproteins
  • Loss of hearing or vision or both

Visiting a neurologist (nerve specialist) may help you correct the problems related to nerves

Treatment Of Monoclonal Gammopathy Of Undetermined Significance

Monoclonal gammopathy of undetermined significance generally does not require any treatment as it does not cause any signs and symptoms. However, your doctor may advise you to get regular follow-ups done, especially if he suspects you to be at an increased risk of getting more serious disorders like multiple myeloma. He will also watch for other signs and symptoms like pain, fever, tingling and numbness, vision and hearing problems, bleeding, anemia, heart and kidney problems etc.

If there is osteoporosis, the doctor may prescribe certain medications to increase the bone density. These may include alendronate, risedronate, etc.


The exact cause of monoclonal gammopathy of undetermined significance is not yet known. However, there are speculations regarding genetic changes, environmental influence and certain infections, to be responsible for this condition. Treatment is not required in most cases.

Also Read:

Pramod Kerkar

Written, Edited or Reviewed By:


Pain Assist Inc.

Last Modified On: February 18, 2019

This article does not provide medical advice. See disclaimer


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