MTHFR stands for methylenetetrahydrofolate reductase. It’s getting attention due to a genetic mutation that may lead to high levels of homocysteine in the blood and low levels of folate and other vitamins.

Its main function is to provide your body with instructions in creating the MTHFR protein, which helps your body produce folate. This B vitamin is necessary to create DNA.

There’s been concern that certain health issues are associated with MTHFR mutations, so testing has become more mainstream over the years.

MTHFR gene variants

You can have either one or two mutations — or neither — on the MTHFR gene. These mutations are often called variants. A variant is a part of a gene’s DNA that’s commonly different, or varies, from person to person.

Having one variant (heterozygous) is less likely to contribute to health issues. Some experts believe that having two mutations (homozygous) may lead to more serious problems.

There are two variants, or forms, of mutations that can occur on the MTHFR gene. The specific variants are:

  • C677T: About 30 to 40 percent of the American population may have a mutation at gene position C677T. Roughly 25 percent of people of Hispanic descent and 10 to 15 percent of Caucasian descent are homozygous for this variant.
  • A1298C: There’s limited research regarding this variant. However, a 2015 study found that A1298C is found in 7 to 14 percent in North American, European, and Australian populations. In comparison, the variant is far less common in Hispanic and Asian populations.

It’s also possible to acquire both C677T and A1298C mutations, which is one copy of each.

Gene mutations are inherited, which means you acquire them from your parents. At conception, you receive one copy of the MTHFR gene from each parent. If both have mutations, your risk of having a homozygous mutation is higher.

However, in cases where a person holds two copies of the C677T mutation or one copy of each mutation, they may be at risk of high homocysteine (an amino acid) levels, which may affect the body’s function.

Symptoms of an MTHFR mutation

Symptoms vary from person to person and from variant to variant. If you do a quick internet search, you’ll likely find many websites claiming MTHFR directly causes a number of conditions.

Keep in mind that research around MTHFR and its effects is still evolving. Evidence linking most of these health conditions to MTHFR is currently lacking or has been disproven.

More than likely, unless you have problems or have testing done, you’ll never become aware of your MTHFR mutation status.

Health conditions and MTHFR mutation

It’s worth noting that the health conditions linked to MTHFR depend on your type of mutation and how many copies you contain.

In cases where you have only one copy of the C677T or A1298C mutation, or two copies of the A1298C mutation, there are typically no health conditions or risks linked.

Conditions that have been proposed to be associated with MTHFR include:

Learn more about having a successful pregnancy with MTHFR.

The risk is possibly increased if a person has two gene variants or is homozygous for the MTHFR mutation.

Testing for MTHFR mutations

Various health organizations — including the American College of Obstetricians and Gynecologists, College of American Pathologists, American College of Medical Genetics, and American Heart Association — don’t recommend testing for variants unless a person also has very high homocysteine levels or other health indications.

Still, you might be curious to discover your individual MTHFR status. Consider visiting your doctor and discussing the pros and cons of being tested.

Keep in mind that genetic testing may not be covered by your insurance. Call your insurance provider if you’re considering getting tested to ask about costs.

Some at-home genetic testing kits offer screening for MTHFR as well. Examples include:

  • 23andMe. This is a popular choice that provides genetic ancestry and health information. It’s also relatively inexpensive ($200). To perform this test, you deposit saliva into a tube and send it via mail to a lab. Results take 6 to 8 weeks.
  • At Home MTHFR. This $80 option specifically focuses on the mutation. The test is performed by collecting DNA from the inside of your cheek with swabs. After shipping the specimen, results take one to two weeks.