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Do I have an MTHFR mutation? Here’s how to find out

Article at a Glance
  • Everyone has MTHFR genes. An MTHFR “mutation” means you inherited a common MTHFR variant associated with a decreased ability to metabolize folic acid and folate.
  • 30% of the population inherits at least one copy of alleles associated with MTHFR “mutations.”
  • Genetic Genie reports are free and will give you a basic read out of your MTHFR status for the most common polymorphisms.
  • For more advanced analysis, the Gene Food Custom Nutrition Plan also reports on MTHFR in the context of methylation status.
  • Science on MTHFR is still emerging and there are vocal skeptics that argue the genes do not have any impact on health outcomes, 23andme being a notable voice.
  • However, many scientists believe there is a strong and growing link between MTHFR C677T and elevated homocysteine, which has been linked to diseases ranging from heart disease and dementia.
Genes Mentioned

So, you’re trying to figure our whether you have the MTHFR gene mutation.” You’re not alone. Commentary on MTHFR has been increasing at a rapid pace over the last few years, with many voices weighing in to both criticize and support associations between MTHFR and risk for disease.

If you want to cut to the chase and find out your MTHFR status, you can take raw data to a site like Genetic Genie for free, or we offer more sophisticated analysis as part of our custom nutrition plan. We list MTHFR status in the “My Genes” section of the report. I have included a screen shot below of the relevant sections.

The first screen shot below is a sample methylation score, which is based on a scoring system that uses 10 SNPs to gauge methylation status.

Next is a full methylation panel as listed in a customer report. As you can see, this customer has one MTHFR SNP, but based on the total methylation score, is still placed into the low risk category by our algorithm.

The blogosphere throws around words like methylation and DNA synthesis, but what are the practical implications of MTHFR polymorphisms and what are the best online sources for finding out whether you carry one of these markers?

We’ll get to all that in a moment, but first some foundational housekeeping to get out of the way.

MTHFR in 30 seconds

MTHFR mutations present issues because of the key role that folate, otherwise known as Vitamin B9, plays at the cellular level in the body.

Through a complex process, we break folate down into methyl folate, which is the “usable” form our bodies need for cell repair, synthesis of new DNA, and the conversion cycle of amino acids.

In the nutrition world, MTHFR causes issues for people when they eat folic acid, which is synthetic B9, and lack the enzymes to convert folic acid into methyl folate.

In short, those with MTHFR mutations can develop problems with synthetic folate in fortified foods, as well as with the amino acid homocysteine, which can pool to unhealthy levels when an MTHFR mutation disrupts the methylation cycle.

How common are MTHFR mutations?

Based on the research Aaron did for our guide to nutrigenomics, we estimate that 30% of people carry at least one copy of the “risk” allele for the two most talked about MTHFR polymorphisms – MTHFR A1298C and MTHFR C677T.

These are common variants that millions of people have. You’re not going to drop dead just because of an MTHFR mutation. Having said that, it’s good to know your status because it can help make nutrition and supplement decisions that could improve your health and quality of life.

Do MTHFR mutations increase risk of disease?

Some commentators are adamant that they do not. For example, 23andme has published blog posts saying there is nothing to link MTHFR mutations and risk for disease. That is definitely one perspective that is out there, and a vocal one at that.

However, many clinicians, and a growing body of science, seem to disagree.

Medical professionals are starting to understand the link between elevated homocysteine and heart disease, dementia and other pathologies. This podcast episode at the 1:19 minute mark is instructive. Renowned physician, Dr. Peter Attia (frequently cited on this blog) interviews Dr. Richard Isaacson, head of the Alzheimer’s Prevention Clinic, who flat out says he used to believe the MTHFR link with dementia was bull crap, but now he doesn’t feel that way.

The mechanism cited is…homocysteine.

And you guessed it, MTHFR mutations, such as C677T, are thought to increase homocysteine in many individuals, especially those with homozygous risk alleles. It makes sense mechanistically since MTHFR is responsible for converting homocysteine to methionine. For more on genes linked to high homocysteine, see this blog post.

It’s also worth taking a look at our MTHFR page as it details the current thinking and the comments section contains a link to an anonymous reader who lists his skepticism over the role of MTHFR mutations in disease (a crux of his argument is that there is a tenuous link between MTHFR and homocysteine, which we disagree with).

So, yes, there does seem to be an emerging link between MTHFR and elevated homocysteine, which is a marker thought to be bad for heart health and cognitive issues. I think the bottom line here is, especially if you identify an MTHFR mutation, it’s probably a good idea to get your homocysteine levels tested as well.

MTHFR and B Vitamins

In some cases, people with MTHFR mutations benefit from supplementing with methylfolate, which is the “bioactive” form of folate. This “gets around” the problems they have with folic acid in particular.

One of the things we do in our custom nutrition plan is estimate methylation ability by analyzing a panel of 10 SNPs, MTHFR included.

This gives us an idea of which individuals may benefit from adding a B complex supplement to their health regimen.

Resources for determining MTHFR mutations

To find out whether MTHFR should be on your radar, you can take raw data from 23andme, or another provider like Ancestry, and upload the data to our site as part of a custom nutrition plan. Your nutrition plan will not only tell you your MTHFR status, it will give you a full methylation analysis as well as a diet type outlining how your body handles fat, carbohydrate, histamine, and more. With that sales pitch out of the way, you can also find out MTHFR status for from a site like Genetic Genie. Genetic Genie can help you determine whether you have one copy, or two copies of either MTHFR C677T, or MTHFR A1298C, the “mutant” versions of the gene.

My MTHFR Story

If you have an MTHFR “mutation,” you could be less effective at getting your body the nutrients it needs to repair DNA.

This can affect you in ways you might not have considered.

For example, I have a heterozygous A1298C MTHFR mutation.

Methyl folate is a co-factor for BH4 (Tetrahydrobiopterin) production, a chemical responsible for creating “feel good” neurotransmitters in the brain. I felt immediate cognitive effects by supplementing with methylfolate shots.

Now, in full disclosure, I received the maximum benefit after adding methylfolate, and other B vitamins, into my supplement regimen after many years of depleted levels. With one MTHFR SNP and an MTRR SNP, combined with too many years of living an unhealthy lifestyle in New York City, my B vitamin levels were low (and I confirmed this via SpectraCell testing). Methylfolate supplements helped tremendously. I can remember taking a client call immediately after taking a B vitamin and methylfolate shot. It felt like the full expanse of my mind had been opened to me. Every word and phrase was right where I wanted it.

See also: Are curcumin’s health benefits proven by human studies?

Now that I take better care of myself, I don’t need as much methyl folate (and most methyl donor supplements aren’t meant to be taken at very high doses indefinitely), but the initial doses, especially after a prolonged period of stress, drinking and eating out a lot in NYC, made a world of difference.

How do you know whether you have an MTHFR mutation?

You start by ordering a 23andme kit, or genetic labs from another provider. 23andme is probably the easiest option, requiring customers to drop a saliva sample in the mail. However, don’t assume getting actionable genetic information from 23andme will be easy. 23andme is restricted by law from giving you some health related information about your genetics, which means you’ll need to download the raw data and take it to a 3rd party.

Here’s how you can do that. 

Once you’ve received your 23andme report, go to the “Tools” section of 23andme’s dashboard, and get your raw data.

Download and save.

Step #1


Step #2

Under Tools, 23andme has a drop down menu. Select “raw data.” You will then land on this page.

You want to download your raw data.

Step #3

23andme will now bring you to this screen, which allows you to request that your raw data be emailed to you.

request raw data 23andme

Now that you have your raw data, you can buy a custom nutrition plan from us or visit a site like Genetic Genie, which will take your raw 23andme data and give you a read out of your methylation genes, including MTHFR.

To make sense of the data you receive, it’s important to remember that MTHFR is the core gene, but within MTHFR, there are different alleles, or options, for the gene to express itself. You’re looking to see whether you have the alleles associated with methylation problems. 

For a quick rundown on the difference between a gene and an allele, check out this video. 

The MTHFR Mutations

The common “mutations” for MTHFR are C677T (linked to heart health) and A1298C (linked to cognitive function). These are types of MTHFR genes. 

Just like there are different types of Ford cars, there are different types of MTHFR genes. The numbers 677 and 1298 represent the base sequence, while the letter represents the allele. The Genetic Genie test is setup to hunt for the presence of alleles linked to diminished methylation performance. For example, everyone has MTHFR 677, but not everyone has the C677T gene, which is the mutated form of C677C, the “normal” allele. Some have the mutation on one side (heterozygous), others on both (homozygous).

Genetic Genie’s methylation analysis lists both MTHFR C677T as well as A1298C. If the line is yellow, you have one copy of the variant for that allele, if the line is red, both copies of the variant are present. If the line is green, you have the normal variant, called normal because it is associated with stronger methylation function. 

See also: Activating the all important Nrf2 pathway using nutrition

As I mentioned above, I have one copy of the A1298C MTHFR mutation. This is what my Genetic Genie report looked like for that line.

A1298C heterozygous

MTHFR mutations do not equal zero function

It’s also important to understand that changes in the base sequence (from cytosine to thymine as with C677T) represent a diminished methylation ability, not zero methylation ability. In other words, even those with copies of the mutant allele, there is still function, and that function can be influenced by epigentic lifestyle factors. 

To quote Genetic Genie:

Although we cannot change our genetic code, we can change how our genes are expressed. Research has revealed that our gene expression is not determined solely by hereditary factors, but it is also influenced by our diet, nutritional status, toxic load and environmental influences or stressors. This phenomenon has been termed “epigenetics”. Researchers in the growing field of epigenetics have demonstrated that certain genes can be over- or under-expressed with certain disease processes.

Epigentics explains why supplementing with methyl folate was so helpful for me after a long stint in New York City. Even a slight decrease in methylation function could be exacerbated by the typical high stress, high alcohol, high caffeine NYC life.

Those with homozygous (two copies of the “mutated gene”) can usually benefit even more from supplementing with methyl folate, vitamin B2 and other B vitamins.

John O'Connor

John O'Connor is the founder of Gene Food. He is passionate about nutrition, genetics, and wellness and uses this blog to publish self experiments as well as some of the research that the Gene Food team does internally to highlight stories of bio-individuality.

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Leave Comment

  1. Tricia says:

    I had some test ran and it came back as Gene MTHFR Genotype C/C (C677T); A/C (A1298C)
    I am having a hard time finding out exactly what this means. Do I have two mutated Genotypes?
    My vitamin B12 is on the low side and I am currently getting weekly injections for four weeks and then will got to once a month, due to the fact that I tried to take sublingual form and it sent me into a heightened anxiety.

  2. Megan says:

    When I get blood tests, my folate level is at the maximum level that they test for. I eat a fairly healthy diet that includes some fortified grains. I also suffer from fatigue and depression. Any insight on my situation?

    • Shannon says:

      Hey Megan, I would suggest getting tested for the HLA-DQ 2 and 8 gene. This test for the celiac gene. You can order it yourself from life extension. I work for a functional doctor and this is something she runs on nearly everyone. It does not necessary mean you have celiac disease but it could show your sensitivities. I recommend you find a functional doctor in general.

  3. Laura Clayton says:

    Hi, I was looking up Information on tongue tie and found my way here. I suffer poor health but the reason why is unknown. I’ve always had bad joints & pain, depression and anxiety and chronic fatigue, lack of concentration and forgetfulness and often I can’t think my brain feels clouded in fog. I was wandering if and how I would go about finding out what may be wrong with me and also how I could make things better. Originally I was looking up tongue tie as my daughter has one but coming across this and different effects and causes has made me think about my own health. Sorry I may not be making a lot of sense its all a lot to take in and I’m not very good at processing information and taking new things in.

  4. Denise says:

    So, to clarify what does the +/- result mean?

    Does that mean you have the gene or that you are a carrier? My report came back for both and they were A/G and G/T

  5. VeenaW says:

    Edited version:
    I just got some lab work back, my B12 level is 1340
    Ive been taking the supplement of active b12(1000mcg + L-5-Methyl-folate(800mcg)
    but also know that the Prenatal D3 I take has folic acid in it at 800mcg.
    I wasn’t consistent daily with either pill before having the blood work done, yet the number is very high.
    I do have HypoThyroid and general issues that come with it. Also had my GGT test done same time and it came back as
    15 u/l . Past 6 months I’ve been pretty good about doing a no sugar, no gluten , no dairy or inflammatory foods. Do you think my high number indicates i don’t handle b12 well?

  6. Aubrey franklin says:

    My sister has both copies of the mthfr gene and I would like to know if I have the same mutations. I would like to order the 23 and me but I’m confused whether I should order the $99 version or the $199 version if I just need to raw data to find out about the mthfr genes. Please help!

  7. Rosemary says:

    Thanks for the article. I am homozygous for 1298C and have sent in my 23andme sample to find out any other SNPs I might need to know about.

    Do you know anyone in Austin who is good at interpreting 23andme genetic data? Any other sites through which it would be good to upload the data?


    • Rosemary, Livewello is a valuable platform for interpreting genetic data in our opinion. If you’re looking for help with nutritional advice, we can assist with that, if you’re looking for medical diagnostics, I don’t know of a place in Austin that I’d recommend. There are some functional medicine docs who claim to be able to interpret genetic data, but I think the medical community is a ways away from coherent and reliable analysis.

    • Martin Evans says:


      Dr. Philip Oubre, MD is a functional medicine doctor in Austin who can interpret 23andMe genetic data. In fact, he sells the 23andMe kits in his office at a marked up price, but recommends that you simply order direct from 23andMe to save some money.

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