MTHFR Testing for Methotrexate Response

Is Testing Right for Me? I Have My Test Results

MTHFR Testing for Methotrexate Response

What Is Methotrexate?

Methotrexate is a drug used to treat cancers and inflammatory diseases. Some common diseases treated include:

  • Rheumatoid arthritis, including polyarticular juvenile rheumatoid arthritis
  • Psoriasis
  • Cancers:
    • Breast cancer
    • Cancers of the head or neck
    • Cancers of the blood (leukemia and lymphoma)
    • Lung cancer
    • Osteosarcoma
  • Prevention of graft vs. host disease in transplants (in combination with other drugs)
  • Molar pregnancy

Methotrexate prevents cells from making DNA, which slows down the growth of cancer cells, and slows the growth of rapidly dividing skin cells that form hard patches of skin in psoriasis. In inflammatory diseases such as rheumatoid arthritis, methotrexate lowers the activity of the immune system, but how it does this isn't well understood.

Side Effects of Methotrexate

In some people, methotrexate can cause serious side effects, especially when it is used in higher doses to treat cancer. One serious problem is called bone marrow suppression. This happens when methotrexate causes the bone marrow to make fewer blood cells, putting the person at risk for dangerous infections. Methotrexate can also damage the liver and the lungs. Doctors call this combination of problems "toxicity." Symptoms to look out for are sore throat, chills, fever, easy bruising and bleeding, extreme tiredness, pain in the upper part of the stomach, yellowing of the skin or eyes, or shortness of breath.

Next: What Affects Methotrexate Response?

Why are you considering MTHFR testing for methotrexate?

I am considering taking methotrexate.

I am currently taking methotrexate and I'm not having any problems with it.

I am taking methotrexate (or have in the past) and experienced side effects.

None of these

You may wish to discuss MTHFR testing for methotrexate response with your doctor. There currently aren't any guidelines for doctors about when to do MTHFR testing for methotrexate response. Your physician can review your personal situation and see if he or she would change your care based on your MTHFR test results, or see if MTHFR results could explain any problems you experienced with methotrexate.

No matter what your MTHFR results might be, it's important to remember that there are many factors that can impact how you respond to methotrexate. Having MTHFR variants doesn't mean you will have side effects for sure. The opposite is also true — even if you don't have any MTHFR variants, there are other reasons why side effects can happen. It is important to be aware of your body and report any possible problems to your doctor right away.

Methotrexate is often given with other drugs. If you are taking methotrexate with 5-FU (5-fluoruracil) or irinotecan, you may wish to read about genetic testing for those drugs:

If you were prescribed methotrexate for Crohn's disease, you may wish to read about genetic testing for Crohn's disease.

MTHFR testing for drug response may not be useful for you. Since you are not taking methotrexate or you have not had side effects from it, testing for MTHFR changes probably will not provide useful information for you or your doctor.

Methotrexate is often given with other drugs. If you are considering 5-FU (5-fluorouracil) or irinotecan, you may wish to read about gene variants associated with responses to those drugs at the following links:

If you were learning about methotrexate for Crohn's disease, you may be interested in the following genetic information about Crohn's disease.

You may wish to discuss MTHFR testing for methotrexate response with your doctor. There currently aren't any guidelines for doctors about when to do MTHFR testing for methotrexate response. Your physician can review your personal situation and see if he or she would change your care based on your MTHFR test results, or see if MTHFR results could explain any problems you experienced with methotrexate.

No matter what your MTHFR results might be, it's important to remember that there are many factors that can impact how you respond to methotrexate. Having MTHFR variants doesn't mean you will have side effects for sure. The opposite is also true — even if you don't have any MTHFR variants, there are other reasons why side effects can happen. It is important to be aware of your body and report any possible problems to your doctor right away.

Methotrexate is often given with other drugs. If you are taking methotrexate with 5-FU (5-fluoruracil) or irinotecan, you may wish to read about genetic testing for those drugs:

If you were prescribed methotrexate for Crohn's disease, you may wish to read about genetic testing for Crohn's disease.

MTHFR testing for drug response may not be useful for you. Since you are not taking methotrexate or you have not had side effects from it, testing for MTHFR changes probably will not provide useful information for you or your doctor.

Methotrexate is often given with other drugs. If you are considering 5-FU (5-fluorouracil) or irinotecan, you may wish to read about gene variants associated with responses to those drugs at the following links:

If you were learning about methotrexate for Crohn's disease, you may be interested in the following genetic information about Crohn's disease.