This condition happens when your bone marrow produces an abnormal protein in your blood. It can sometimes progress to certain types of blood cancer.
Monoclonal gammopathy of undetermined significance (MGUS) is a condition in which an abnormal protein — known as monoclonal protein or M protein — is in your blood.
This abnormal protein is formed within your bone marrow, the soft, blood-producing tissue that fills in the center of most of your bones. The disorder occurs most commonly in older men.
MGUS usually causes no problems. But sometimes it can progress to more-serious diseases, including some forms of blood cancer.
If you have high amounts of this protein in your blood, it's important to have regular checkups so that you can get earlier treatment if it does progress. If there's no disease progression, MGUS doesn't require treatment.
People with monoclonal gammopathy generally don't experience signs or symptoms. Some people may experience a rash or nerve problems, such as numbness or tingling. MGUS is usually detected by chance when you have a blood test for another condition.
The precise cause of MGUS isn't known. Genetic changes and environmental triggers appear to play a role.
Factors that increase your risk of developing MGUS include:
Each year about 1% of people with MGUS go on to develop certain types of blood cancers or other serious diseases such as:
Other complications associated with MGUS include bone fractures, blood clots and kidney problems.
Because MGUS usually causes no symptoms, it's usually detected by chance during blood tests for other conditions. Afterwards, your doctor may recommend:
MGUS doesn't require treatment. But your doctor is likely to recommend periodic checkups to monitor your health, probably starting six months after your diagnosis.
If you are at high risk of MGUS developing into a more serious condition, your doctor may recommend more frequent checkups so that any progression can be diagnosed and treatment started as soon as possible.
Your doctor is likely to watch for signs and symptoms such as:
If you have osteoporosis, your doctor might recommend a medication to increase bone density. Examples include alendronate (Fosamax), risedronate (Actonel, Atelvia), ibandronate (Boniva) and zoledronic acid (Reclast, Zometa).
You may be referred to a doctor who specializes in blood disorders (hematologist).
It's a good idea to be well-prepared for your appointment. Here's some information to help you get ready, and what to expect from your doctor.
For MGUS, some basic questions to ask your doctor include:
Don't hesitate to ask other questions you have.
Your doctor is likely to ask you a number of questions, including: