National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Monoclonal gammopathy of undetermined significance

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Other Names:
MGUS
Monoclonal gammopathy of undetermined significance (MGUS) is a condition in which an abnormal protein called monoclonal protein is detected in the blood. MGUS typically does not cause any problems, although some affected people may experience numbness, tingling or weakness. In some cases, MGUS may progress over time to certain forms of blood cancer (such as multiple myeloma, macroglobulinemia, or B-cell lymphoma). MGUS is thought to be a multifactorial condition that is likely associated with the effects of multiple genes in combination with lifestyle and environmental factors. People with MGUS are usually monitored closely to ensure that the levels of monoclonal protein do not rise and other problems do not develop. Those with stable levels of monoclonal protein typically do not require treatment.[1][2]
Last updated: 12/27/2016

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Monoclonal gammopathy of undetermined significance. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • The International Myeloma Foundation provides information on monoclonal gammopathy of undetermined significance.
  • MayoClinic.com has an information page on monoclonal gammopathy of undetermined significance. 
  • The Merck Manual provides information on this condition for patients and caregivers. 

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Merck Manual for health care professionals provides information on Monoclonal gammopathy of undetermined significance.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Monoclonal gammopathy of undetermined significance. Click on the link to view a sample search on this topic.

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  1. Monoclonal gammopathy of undetermined significance (MGUS). Mayo Clinic. May 2013; http://www.mayoclinic.org/diseases-conditions/mgus/basics/definition/con-20026422.
  2. Suzanne R Fanning, DO. Monoclonal Gammopathies of Uncertain Origin. Medscape Reference. 2016; http://emedicine.medscape.com/article/204297-overview#a0104.