Methylenetetrahydrofolate Reductase Mutations

Methylenetetrahydrofolate reductase mutations, also called MTHFR mutations, is a test to:

  • evaluate the cause of elevated homocysteine levels
  • sometimes to help determine your risk of thrombosis or premature cardiovascular disease (CVD)
What does the test results mean?

There are two MTHFR variants called C677T and A1298C. The test results are typically reported as negative or positive.

If the test is negative, then the C677T and A1298C mutations were not detected. The tested person’s elevated homocysteine level may due to another cause.

If the test is positive, it means there are MTHFR C677T and A1298C mutations. The interpretation is as follows:

  • If a person has two copies of MTHFR C677T, or has one copy of C677T and one of A1298C, then the elevated homocysteine levels may be due to inherited mutations.
  • Two copies of A1298C are not typically associated with increased homocysteine levels.

People with MTHFR mutations and other clotting risk factors may be also at an increased risk of thrombosis.


Keywords: methylenetetrahydrofolate reductase mutations; MTHFR mutations

* The contents of this HTQ Site are for informational and communicational purposes only. The information provided by HTQ, HTQ employees, others appearing on the Site at the invitation of HTQ, or other visitors to the Site is NOT a medical advice.The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on the HTQ Site!