MTHFR gene mutations are the root of all health problems – and vaccines

I have a love-hate relationship with the internet. I love that I can Google a question like “who was the second basemen for the Pittsburgh Pirates in the 1960 World Series?” It was Bill Mazeroski for those who care. I don’t love that you can search for “MTHFR gene mutations,” and get a lot of nonsense.

Although I think that Wikipedia needs to be used skeptically, it is a wonderful fountain of delicious knowledge. I sometimes just read random Wikipedia articles, and I enjoy the writing, scholarship and knowledge. Some articles, like World War II or the Roman Empire, are truly detailed pieces of scholarship.

But sometimes, the internet does a disservice to mankind, especially when medical information (or really disinformation) is presented as fact. Like vaccines cause autism. No, it doesn’t. Seriously, it doesn’t.

Or that chronic lyme disease actually exists. No it doesn’t.

Or that high fructose corn syrup causes obesity and diabetes. No it doesn’t (except that eating a lot of any sugar might do that).

But the newest one, at least for me, is that MTHFR gene mutations cause nearly every disease known to mankind, and is a reason why vaccines can be dangerous. Seriously, apparently MTHFR gene mutations are the root of all health evil, and the mutation is caused by…anything.

What is this MTHFR gene?

Methylene tetrahydrofolate reductase (MTHFR) is the rate-limiting enzyme in the methyl cycle, and it is encoded by the MTHFR gene. In other words, the MTHFR gene is responsible for production of an important enzyme.

This enzyme is a critical part of the methionine and folate cycles, which are important to manufacturing methionine, an amino acid which is a fundamental constituent of all proteins on the planet, and  folate (or folic acid), which is an essential nutrient.

"MTHFR metabolism" by Epgui - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons

As obvious in the chart above, the MTHFR gene has a central role in a very complicated biochemical pathways. MTHFR enzyme deficiency (caused by one of several MTHFR gene mutations) leads to two important problems:

  2. Lack of folate (folic acid), which leads to several known issues, is  easily treated with folate or folic acid. As I’ve discussed in scientifically detailed manner previously, folate and folic acid are simply two forms of the same chemical, indistinguishable by the human biochemistry.


Genetic variation in this gene may influence susceptibility to peripheral artery disease, neural tube defectsAlzheimer’s disease and other forms of dementia, colon cancer, and acute leukemia. Additionally, variations of MTHFR gene mutations have been studied in connection to stroke, high blood pressure and heart disease, as well as bipolar disorder and other conditions. However, these associations have not been established by high quality case-controlled epidemiological studies, there are only some preliminary observations that probably need to be investigated more fully.



Your child can “catch” a mutation of the MTHFR gene

Absolutely not. One of the several mutations of the gene is generally passed from the genetic material of one of the child’s parents. It is either there or not there (although there is a tiny chance that the mutation might form in the developing embryo, but that’s awfully rare).

When the fetus is developing, you cannot cause a mutation in one (or even several cells) and that mutation spreads to the whole fetus. That’s not how it works, genes from one cell do not “infect” other cells of the developing fetus. If that kind of genetic transfer were so easy, gene therapy would be the easiest treatment known to medicine.

An infant, child or adult cannot have one of several MTHFR gene mutations spread through the whole body. So, vaccines, gluten, GMO foods, mercury, unfiltered water, fluoride or whatever nonsense known to the internet cannot induce a mutation in a whole body. It is possible that the original MTHFR gene mutations in the parental genotype were originally caused by some environmental factor, but it could have happened many generations before.

Don’t vaccinate a child with MTHFR gene mutations?

There is no evidence of this danger, despite widespread internet rumors and myths to the contrary.

There is precisely one published article, published in the Journal of Infectious Diseases nearly 7 years ago, that examined adverse events after a smallpox vaccination being associated with MTHFR gene mutations. What they concluded was:




In other words, they found some evidence, but the evidence did not support a conclusion that vaccinating individuals with the MTHFR had increased adverse events.

Moreover, they state that biological plausibility needs to be established first. There is not much biological plausibility that  a vaccine can be associated with the MTHFR enzyme.  Though the folate and methionine cycles appear to be complex, they are isolated from other biochemical pathways in the body because they occur within cells. And individuals who are being successfully treated for the consequences of MTHFR gene mutations probably wouldn’t be affected by vaccines.

Unless you ascribe to the logical fallacy of the precautionary principle, meaning you need to have evidence that there are no risks whatsoever, then there really is nothing here. But I guess we could waste money, like we did debunking the vaccines cause autism myth.

Quacks and MTHFR gene mutations

One internet quack, Ben Lynch, a naturopathic “doctor” (pure pseudoscience), tries to make the claim that MTHFR gene mutations cause a whole host of diseases, using “peer-reviewed” articles. Many of the studies are just plain cherry picking, choosing research that supports his point of view, rather than looking at studies that dispute it. Other articles are published in really low ranking journals, or he completely misinterprets the evidence.

For example, Mr Lynch (he is not a real doctor, so he doesn’t get that title) claims that one of the MTHFR gene mutations is related to colon cancer. This research can be easily disputed by:

  2. It uses a small population (about 300 subjects) in one small area of China. That is not a representative sampling of a large population, so there might be inherent bias in any results.



But the most glaring and horrific error in his list of “research” was a claim that thiomersal was associated with autism with those who have one of the MTHFR gene mutations. The evidence comes from, an antisemitic, hate-filled, chemtrail believing website run by a pig farmer. I kid you not.

Using as your evidence, which ranks at the bottom of the hierarchy of scientific evidence, is almost sufficient to dismiss everything that Mr Lynch claims with respect to MTHFR gene mutations, because if he couldn’t use real science there, it’s obvious that he really doesn’t understand science. But then again, Lynch is a woo-pushing naturopath, so there’s that.

The TL;DR version


Editor’s note: This article was originally published in May 2015. It has been extensively revised and updated to include more comprehensive information, to improve readability and to add current research.


Key citations:

  • Reif DM, McKinney BA, Motsinger AA, Chanock SJ, Edwards KM, Rock MT, Moore JH, Crowe JE. Genetic basis for adverse events after smallpox vaccination. J Infect Dis. 2008 Jul 1;198(1):16-22. doi: 10.1086/588670. Erratum in: J Infect Dis. 2008 Sep 1;198(5):796. PubMed PMID: 18454680; PubMed Central PMCID: PMC2746083.



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The Original Skeptical Raptor
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