MTHFR

[[File:Secondary structure of MTHFR.svg|thumb|right|Secondary structure (structure of proteins that show alpha-helices and beta-sheets) of '''MTHFR'''. <br>The "spirals" symbolize alpha-helices (α-helices) while the "arrows" stand for beta-sheets (β-sheets). <br>The numbers on these elements denote the [[amino acid]] position (i.e. where on the total sequence a particular structure begins and ends). <br>N and C denote, respectively, the beginning (amide group: -CONH<sub>2</sub>) and the end (carboxyl group: -CO<sub>2</sub>H) of the protein.]]
{{Biology}}
'''Methylenetetrahydrofolate reductase''' ('''MTHFR''') is an [[enzyme]]<ref>https://ghr.nlm.nih.gov/gene/MTHFR</ref> related to the methyl cycle involved in B vitamins. Many people have variations (usually harmless) in the ''MTHFR'' gene.

Despite its spelling, it is not an abbreviation for Samuel L. Jackson's most well-known expletive.

==Role in health conditions==
[[Mutation]]s in the MTHFR gene have been proposed to be linked to everything from [[autism]] to nerve pain to [[Cancer|leukemia]].<ref>[https://www.healthline.com/health/mthfr-gene#treatment What You Need to Know About the MTHFR Gene]</ref> Some early studies suggested that people with certain [[disease]]s had MTHFR variants, only for researchers to discover that the variants were just as common in healthy people.<ref>[https://www.theatlantic.com/science/archive/2019/05/vaccines-dna-23andme/589915/ Why Anti-vax Doctors Are Ordering 23andMe Tests]</ref> Many of these proposals nowadays come from [[naturopath]]s and [[quack]]s, based completely on [[anecdotal evidence]].<ref>[https://sciencebasedmedicine.org/dubious-mthfr-genetic-mutation-testing/ Dubious MTHFR genetic mutation testing]</ref>

In most cases, however, people with MTHFR variants just need a little extra vitamin B.<ref>[https://www.healthline.com/health/mthfr-gene#treatment What You Need to Know About the MTHFR Gene]</ref> Their levels of homocysteiene may be average or above average. An above-average level may put them at higher risk for a few health conditions.<ref>[https://rarediseases.info.nih.gov/diseases/10953/mthfr-gene-mutation MTHFR gene variant]</ref>

===Unclear associations===
Research is not yet clear on whether people with MTHFR variants are at higher risk of heart disease, blood clots, [[cancer]], and other conditions.<ref>[https://blog.23andme.com/health-traits/our-take-on-the-mthfr-gene/ Our Take On The MTHFR Gene] - 23andMe</ref>

===Neural tube defects===
Children of people with two C677T variants are at 0.14% risk that they will have a neural tube defect. A folate supplement will reduce this risk.<ref>[https://rarediseases.info.nih.gov/diseases/10953/mthfr-gene-mutation MTHFR gene variant]</ref> If neural tube defects run in the family, prospective parents can consult a doctor about an appropriate supplement.

===Homocystinuria===
Homocystinuria is a rare condition related to impaired metabolism of folate (vitamin B<sub>9</sub>) due to MTHFR enzyme deficiency. It is present from [[birth]] and can be treated with supplements. Symptoms include (from most to least common):<ref>[https://rarediseases.info.nih.gov/diseases/2734/homocystinuria-due-to-mthfr-deficiency Homocystinuria due to MTHFR deficiency]</ref>
*Developmental delay and intellectual disability
*Low muscle tone
*Seizures
*Failure to thrive
*Abnormal blood clotting
*Microcephaly (small head)
*Ataxia (poor coordination)
*Peripheral neuropathy (numbness, tingling, or pain in the hands and feet)

==Pseudoscience==
{{main|Pseudoscience}}
[[Scam]] artists encourage people to test for MTHFR variants and send their [[genetic]] information to the scammer. Then, the scammer can find things that are "wrong" with the person and sell them supplements, [[Fad diet|restrictive diets]], and other "solutions". However, experts consider MTHFR testing to be unnecessary, except in unique cases,<ref>[https://sciencebasedmedicine.org/dubious-mthfr-genetic-mutation-testing/ Dubious MTHFR genetic mutation testing]</ref> and some have gone so far to recommend against it so that patients do not waste their time.<ref>[https://www.forbes.com/sites/brittmariehermes/2016/11/14/genetic-sequence-exploited-supplement-industry/#410087e82e67 How Your Genetic Sequence Can Be Exploited By The Supplement Industry]</ref><ref>[https://www.acmg.net/docs/MTHFR_gim2012165a_Feb2013.pdf ACMG Practice Guideline: lack of evidence for MTHFR
polymorphism testing] (PDF)</ref>

The supplements they sell may not be safe, either. Taking too much folic acid may increase the risk and severity of cancer.<ref>[https://www.forbes.com/sites/brittmariehermes/2016/11/14/genetic-sequence-exploited-supplement-industry/#410087e82e67 How Your Genetic Sequence Can Be Exploited By The Supplement Industry]</ref>

===MTHFR and vaccines===
Despite rumors, children with MTHFR variations can be vaccinated normally.<ref>[http://www.skepticalraptor.com/skepticalraptorblog.php/mthfr-gene-mutations-are-the-root-of-all-health-problems/ MTHFR gene mutations are the root of all health problems – and vaccines]</ref>

===Fake autism cures===
Researchers are still cautious about whether there is a meaningful link between polymorphism in the MTHFR gene and [[autism]].<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4241316/ MTHFR Gene C677T Polymorphism in Autism Spectrum Disorders]</ref><ref>[https://www.ncbi.nlm.nih.gov/pubmed/23653228 Association between MTHFR gene polymorphisms and the risk of autism spectrum disorders: a meta-analysis.]</ref> Yet charlatans have charged on ahead to sell fake autism cures claiming to be related to MTHFR. These "cures" can cost thousands of dollars, and they give families [[false hope]] of changing their children (instead of just accepting that their kid is autistic).<ref>[https://www.independent.co.uk/news/world/americas/autism-cures-promised-by-dna-testers-belied-by-regulators-8430767.html Autism cures promised by DNA testers belied by regulators]</ref>

==See also==
*[[Anti-vaccination movement]]
*[[Vitamin and mineral supplements]]

==References==
{{reflist|2|80%}}

[[Category:Autism woo]]
[[Category:Biology]]
[[Category:Genetics]]

Categories: Autism woo, Biology, Genetics