The MTHFR gene mutation is fairly common in the general population. There are a few different areas of health where knowledge of an MTHFR mutation can be important. What exactly is it and what does it do in our bodies?
The MTHFR gene provides genetic instructions to make a protein that helps your body process something called folate. Folate is important in your body to make DNA and alter proteins. We all have different changes in our DNA or genetic instructions, and some of those changes are disease-causing (typically called mutations) and others just make us different from each other (typically called variants). There is one variant in the MTHFR gene that changes a single letter in our genetic instructions that make up the MTHFR gene. Depending on what that letter is at that location, a person will have a particular variant of the MTHFR gene.
There are three common variants of the MTHFR gene. To review, we all have two copies of every gene in our body, one from our mother and one from our father. For the MTHFR gene, we can inherit two copies of the C variant (MTHFR 677 CC), one copy of C and one copy of T (MTHFR 677 CT), or two copies of T (MTHFR 677 TT). For those individuals who have two copies of T in the MTHFR gene, the average amount of folate in their bodies is about 16% lower than people with two copies of the C in the MTHFR gene.
There is one other common gene variant in the MTHFR gene called MTHFR A1298C, where at the 1298 position in our DNA the letter is changed from A to a C. Currently, there is not enough evidence that this MTHFR variant by itself affects how our bodies process folate.
The important takeaway of learning about the MTHFR gene is that regardless of which variant you have, it is important to have enough folate in your body. Folate is a form of Vitamin B9. A synthetic form of Folate is called Folic Acid. There are folic acid supplements available, or a variety of foods that have folate, such as leafy green vegetables, citrus fruits, and beans.
Research has shown that women who have two copies of T in the MTHFR gene variant are at increased risk of having a pregnancy affected by a neural tube defect. Studies have shown that neural tube defects can be prevented by supplementing during pregnancy with folic acid. Every woman is recommended to take folic acid during pregnancy, especially in the first trimester as the neural tube is developing in a fetus. For women who have two copies of T in the MTHFR variant, it may be recommended by their health care provider to take a higher dose of folic acid.
In addition, for both men and women who have two copies of T in the MTHFR gene variant, there may be a slightly increased risk to develop blood clots. If you have a family history of blood clots and a known MTHFR variant that increases your risk, it is important to notify your health care provider. However, typically the risk of developing a blood clot is so small a health care provider may not change your medical care. Your health care provider may look for additional reasons why your family has a history of blood clots.
These MTHFR gene variants are passed down from parents to children. Each family member has a 50% chance to inherit a particular MTHFR gene variant found in your family.
If you are interested in learning more about your risks associated with an MTHFR gene variant, have a pregnancy history of neural tube defects, or a family history of blood clots, please contact AT-GC to meet with a genetic counselor.