Article at a Glance
- Several tests report on the two most common MTHFR gene variants – C677T and A1298C.
- MTHFR gene variants are relatively common, with roughly 35% of the population in North America carrying at least one copy of the C677T variant.
- Analyzing MTHFR genes in conjunction with other SNPs in the methylation pathway as part of a polygenic risk score will provide the most insight.
Of all the genes in the world of nutrigenomics, MTHFR is probably the best known. In fact, MTHFR has been thrust into the spotlight again after Gary Brecka appeared on Joe Rogan to discuss the importance of DNA methylation and monitoring homocysteine levels.
If you’re wondering whether you “have MTHFR,” you needn’t. Everyone has MTHFR genes, it’s just that some of us carry variants that reduce the function of the gene’s activity and its role in converting folate into a form the body can utilize.
Because variants in the MTHFR genes are quite common, many in the genetics world, such as 23andme, recommend against testing for mutations at all.
While we agree that the “symptoms” blamed on changes in the MTHFR genes are wildly overstated in the functional health world, failing to test altogether is a mistake, especially for the Black community, where the clinically significant variants are far less common.
If you are wondering whether you carry common variants in the MTHFR genes called SNPs, there are a number of tests that report on these genes.
DNA test kits that include MTHFR variants
Below are the top 4 DNA test kits that test for MTHFR variants. These tests report on several MTHFR variants, including the two most popular SNPs, which are rs1801133 (C677T) and rs1801131 (A1298C).
What will the results tell me?
MTHFR (methylenetetrahydrofolate reductase) is the enzyme produced by the MTHFR gene. It’s required for metabolizing folate and breaking down the amino acid homocysteine.
As a general rule, an MTHFR test will tell you whether your body has an enhanced need for folate, over and above dietary recommendations. Getting adequate folate in the diet is an important factor in keeping homocysteine levels in a healthy range.
How to find MTHFR for 23andme users
If you have already purchased a 23andme test kit, you can login to see your MTHFR status by downloading your raw genetic data.
If you have a 23andme account, you can login and see your MTHFR status in a few simple steps.
Step #1 – login and select “browse raw data”
23andme has made it much easier to navigate to your raw data file from the dashboard of a logged in account.
Step #2 – search MTHFR
Once you arrive at the raw data screen, you can search genes by name and see your call for the various SNPs they report on.
There are many different MTHFR genes, although we will focus on a couple that are thought to be most clinically relevant. As you can see from the screen below, I typed in MTHFR directly into the 23andme search bar.
Step #3 – find the right version of the MTHFR gene
Once you arrive at the raw data search field for 23andme, you simply scroll down the page and find the relevant rsID of the MTHFR gene you’d like to evaluate.
You will see numerous results with your status for each under the “Your Genotype” column. The most researched MTHFR variants are MTHFR C677T (rs1801133) and MTHFR A1298C (rs1801131).
First, stop and notice how similar the rsID numbers are for these genes!
Next, scroll the “Marker / SNP” column and find these variants. Minor allele for A1298C is – C or G. Minor allele for C677T is – T or A.
If 23andme shows one copy of the minor allele that represents a “heterozygous” mutation. If two copies, that is a homozygous mutation. Here you can see Here, you can see my call for MTHFR C677T is G/G, meaning I do not carry a risk allele.
Why we don’t recommend Gary Brecka’s MTHFR test
John has written separately about the excessive pricing and limited coverage in the genetic tests offered by Gary Brecka and his company 10X Health.
If you are interested in learning your MTHFR status, we recommend going with one of the providers listed in this article for two reasons:
- Brecka’s test only looks at 5 genes total (which isn’t enough information to learn much of anything about your overall state of health)
- The price point is excessive for the limited number of genes tested
We have a blog post on our site detailing the various sites that process 23andme raw data.
MTHFR is also one of the genes we report on in the methylation section of our custom nutrition plans.