Fact Check: Birthmarks NOT Caused By MTHFR Gene Variants, Which Rarely Cause Disease, Are NOT Harmful For Those Receiving Vaccines

Fact Check

  • by: Arthur Brice
Fact Check: Birthmarks NOT Caused By MTHFR Gene Variants, Which Rarely Cause Disease, Are NOT Harmful For Those Receiving Vaccines Not Proven

Do variants of the MTHFR gene cause disease and increase the likelihood of vaccine reactions? No, that's not true: In rare circumstances, a MTHFR (methylenetetrahydrofolate reductase) gene variant causes neural tube defects in newborn babies. Other times, it can cause elevelated levels of homocysteine, which can lead to blood clots. Otherwise, there are no scientific studies linking MTHFR gene variants, often called mutations, to any diseases or vaccine reaction. And certainly no relation has been found to the skin conditions shown in the photos, which are relatively common and benign.

The claim appeared in a post (archived here) published on Facebook on November 13, 2018. It opened: "Take a look at these pictures. Have you or your child ever had any of these marks?" It continued:

These are indicators of the MTHFR gene.
The MTHFR gene is involved in a process called "methylation." Methylation determines how genes are expressed, how enzymes function, and how your body clears toxins. Our body needs to be able to detox properly with the amount of toxins we come in contact everyday.
If this "methylation system" isn't working right ... you could experience depression, fibromyalgia, migraines, autism, birth defects, low energy, infertility, elevated levels of homocysteine, gotta sleep right now fatigue, IBS, ADD/ADHD, migraines, thyroid disfunction, metabolism disorders, autoimmune diseases, and even cancer...When people have MTHFR their chances of vaccine reactions increase because they cannot detox the toxins from the vaccines.

This is what the post looked like on Facebook at the time of writing:

Facebook screenshot

(Source: Facebook screenshot taken on Wed Dec 23 14:22:55 2020 UTC)

Before starting to explain what the MTHFR gene and its variants are and what they do and don't do, it's necessary to point out that the skin conditions shown in the photographs -- stork bite, sugar bug and sacral dimple -- are all common and harmless. None of them have been linked in scientific studies to an MTHFR gene mutation. Here's a quick overview:

On stork bites, the Healthline website explains that:

  • Stork bite birthmarks are common. They appear on 30 to 50 percent of newborn babies.
  • They can be inherited, but often there's no known cause.
  • The birthmark develops when blood vessels underneath the skin become stretched or dilated.

The web site what to expect details what sugar bugs are:

  • Visible vein on the bridge of an infant's nose and between the eyes. Officially known as a prominent dorsal nasal vein, a sugar bug usually becomes less visible as the child grows, with no treatments necessary.
  • Although a sugar bug might look worrisome, it doesn't indicate anything. It may simply mean that the baby has light and/or thin skin.
  • Despite some erroneous claims that sugar bugs indicate something about a child's future health (like that they're a predictor of digestive problems or ADHD), there is no scientific evidence or rationale linking these veins to any other condition.
  • It's perfectly normal for babies to have sugar bug veins. In fact, all humans have the same vein; it's just not always visible.

About sacral dimples, Healthline says:

  • A sacral dimple is a small, usually shallow indentation in the small of the back, just above or within the crease of the buttocks.
  • About 3 to 8 percent of the population has a sacral dimple. A very small percentage of people with a sacral dimple can have spinal abnormalities.
  • In most cases, a sacral dimple causes no problems and isn't associated with any health risks.
  • Scientists aren't exactly sure what causes a sacral dimple. It's a congenital condition, which means a person is born with it. It forms for unknown reasons during fetal development. There are no risk factors for developing a sacral dimple.

Dr. Justin Smith, a pediatrician and the Medical Advisor for Digital Health for Cook Children's in Fort Worth, Texas, wrote in a blog posting on February 14, 2020:

I have searched the literature for any connected between these findings and MTHFR mutations. No studies exist.

Nor are there any studies substantiating any connections between MTHFR gene variants and adverse health effects in relation to vaccinations. Here's what we know:

Everyone has two copies of the MTHFR gene, one inherited from the mother, the other from the father. The National Institute of Health explains in a publication updated August 18, 2020 that:

The MTHFR gene provides instructions for making an enzyme called methylenetetrahydrofolate reductase. This enzyme plays a role in processing amino acids, the building blocks of proteins.

The NIH further spells out in another publication updated January 25, 2018:

As is true for any gene, the DNA code of the MTHFR gene can vary. When we identify a part of the sequence that varies, we call it a "variant." Genetic research aims to identify specific variants that cause harm or benefit to health.

There are two MTHFR gene variants, called C677T and A1298C, that have been an active area of study. These variants are common. In America, about 25% of people who are Hispanic, and 10-15% of people who are Caucasian have two copies of C677T.

Studies have found that women with two C677T gene variants have an increased risk for having a child with a neural tube defect. Studies have also found that men and women with two C677T gene variants and elevated homocysteine levels may be at a mild increased risk for blood clots (venous thromboembolism).

The CDC explains that the changes in the MTHFR gene are variants, not mutations:

Gene variants are common and normal. In fact, there are more people in the United States who have one or two copies of the MTHFR C677T variant than people who do not have it. Variants in genes are what make us unique. They cause differences, such as eye color, hair color, and blood type.

You may have seen the MTHFR C677T variant referred to as a "gene mutation;" however, the word, 'mutation,' usually refers to a change in the gene that is much less common. It is more accurate to refer to MTHFR C677T as a "gene variant."

The Facebook posting is correct that MTHFR is involved in methylation. But it draws a faulty conclusion as to how MTHFR variants might affect methylation.

Psychiatrist Judy Tsafrir details it in the November 22, 2017 issue of Psychology Today:

Methylation is a vital foundational biochemical process in the body, involved with the detoxification of heavy metals, regulation of gene expression and protein function, and central to the synthesis of neurotransmitters, the chemical messengers which mediate mental and emotional states. Imbalances in methylation status result from genetic defects in the enzymes which regulate the process of methylation. In the past few years there has been a great deal of interest in genetic testing, and in particular, the role of the MTHFR gene. A genetic defect of the MTHFR gene can result in a malfunctioning MTHFR enzyme, which can affect methylation.

There is a common misconception, however, that the mere presence of an MTHFR mutation is synonymous with a methylation defect. This is by no means necessarily the case ... The presence of the defective gene does not necessarily translate into a functional defect.
This assertion is buttressed in a December 7, 2017 article in NDs For Vaccines titled "MTHFR and Vaccination: Much Ado About Nothing." The article concludes that:
... the claim that MTHFR affects liver detoxification pathways has not been proven. It's not that liver detoxification hasn't been studied. ... But the pathways that MTHFR affects are not involved in liver detoxification.
Some observers believe the purported link between MTHFR and vaccinations dates to a 2008 research paper that tied a variant of the MTHFR gene to "adverse events" from receiving a smallpox vaccine. The paper was even cited in an unsuccessful 2016 lawsuit by a vaccine-skeptical physician, The Atlantic says in a May 23, 2019 article.
But now, The Atlantic says, that study's lead author, David Reif, has renounced his own conclusions, saying:
It's just not even a valid study by today's methodology.
The study is no longer valid, he said, because it is:
... emblematic of that early, now outdated genetics research. The paper was composed of two small studies, one with just 85 participants and the other with 46. To get published today, such studies would likely need thousands of participants and to have validated the results in a second group of people. 'We were just starting to figure out how to use the genome,' Reif says. The tools they used -- along with so many other geneticists at the time -- were simply not up to snuff.
Furthermore, the study only covered smallpox vaccines, which are no longer given to children, as the disease has been officially eradicated since 1980. ... And the 'adverse events' were simply mild fevers and rashes ...
Many antivaccination health practioners are telling their patients to have genetic testing done to see if they have MTHFR variants. That led 23andMe, one of the leading companies that performs genetic testing, to look into the MTHFR claims. Those claims are baseless, the company said in a January 5, 2017 posting:
Despite lots of research - and lots of buzz - the existing scientific data doesn't support the vast majority of claims that common MTHFR variants impact human health.
Here's why, 23andMe said:
First, it's unlikely that variants in a single gene could cause dozens of unrelated health problems. Second, the C677T and A1298C variants are very common: in some ethnicities, more than 50 percent of people have at least one copy of one of these variants. Most disease-causing genetic variants are not this common.
Over the past two decades, scientists have examined associations between the MTHFR C677T and A1298C variants and more than 600 medical conditions. Despite thousands of scientific publications, the evidence linking MTHFR to most of these health conditions is inconclusive or conflicting.
Which led the company to conclude:
In order for a connection between a genetic variant and a health condition to be considered real and clinically meaningful, well-run scientific studies need to show convincing and consistent evidence for that association. As statements from multiple scientific and medical organizations indicate, that is currently not the case for the common MTHFR variants.
It should be noted that MTHFR variants are considered so medically insignificant that major medical associations recommend against testing for it, according to a National Institutes of Health undated report:
The American Congress of Obstetricians and Gynecologists (ACOG) and the American College of Medical Genetics recommends against testing for common MTHFR gene variants. Common MTHFR gene variants have not been proven to be a concerning risk factor for blood clots, pregnancy loss, or other negative pregnancy outcomes.

The American Heart Association recommends against testing for the common MTHFR gene variants or homocysteine as a screen for increased risk of cardiovascular conditions. The Association does not consider MTHFR a major risk factor for heart disease.

The College of American Pathologists, the American College of Medical Genetics, and the American Heart Association recommend against testing for C677T and A1298C in people with blood clots. This is because results have little impact on a persons medical management.
In addition to a lack of scientific proof through studies, there's also a dearth of adverse reactions to vaccines. NDs For Vaccines notes:
Given how common the C677T and A1298C polymorphisms are, if they did cause problems with vaccination, we would see a much higher rate of significant adverse events. However, the rate of serious adverse events is much, much, much lower -- by many orders of magnitude -- than the occurrence of C677T and A1298C in the population. Fewer than one in a million children have a serious reaction to a vaccination ...
Genetic Lifehacks sums up the evidence succintly in a January 20, 2020 posting:
No scientific evidence pointing to the common MTHFR variants playing a role in vaccination adverse events.

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Lead Stories is working with the CoronaVirusFacts/DatosCoronaVirus Alliance, a coalition of more than 100 fact-checkers who are fighting misinformation related to the COVID-19 pandemic. Learn more about the alliance here.


  Arthur Brice

Arthur Brice is a fact checker at Lead Stories. He has been a journalist for more than 40 years, nearly 30 of them in newspapers. Brice was a national desk editor and reporter at The Atlanta Journal-Constitution for nearly 20 years. Previously, he was political editor at The Tampa Tribune and also worked for three other Florida newspapers. He spent 11 Years as an executive editor and executive producer at CNN. 

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