What are MTHFR gene mutations?
MTHFR is an abbreviation for the MTHFR gene that produces an enzyme called methylenetetrahydrofolate reductase (MTHFR). Methylenetetrahydrofolate reductase is a very important enzyme for vitamin B9 metabolism (Folate) and homocysteine regulation. With your 23andme raw data, you can learn a lot about your MTHFR enzyme.
MTHFR enzyme performs the function of adding chemical (methyl) groups to folic acid (Vitamin B9) in order for the body to utilize it efficiently. This process is known as methylation. Methylation causes changes in the genetic material without changing the underlying genes.
People with MTHFR gene variations may have an increased or decreased level of efficiency in converting folate to methylfolate. This has been linked to several conditions such as an increased risk of higher homocysteine levels, neural tube defects like spina bifida and anencephaly, heart disease, stroke, preeclampsia, and many psychiatric disorders.
Studies indicate that 45% of the population might harbor the risk variant of the MTHFR gene. This hampers the methylation of homocysteine, resulting in decreased levels of the enzyme methionine and higher levels of homocysteine in many individuals.
What is an MTHFR test? Who can take an MTHFR test?
An MTHFR gene test examines variations in the MTHFR gene. This test does not need a medical prescription. It can be performed in a major genetic diagnostic lab such as Quest or LabCorp. More readily, the 23andme MTHFR status can be determined from your 23andme raw data. Anyone with 23andme raw data can upload their DNA raw data to a variety of service providers to learn about their 23andme MTHFR status. So the MTHFR “test” is not necessarily a test but can be as simple as uploading your 23andme raw data and downloading your results.
In an MTHFR gene evaluation, the DNA is retrieved from a saliva sample. The sequence of your DNA is then genotyped for the most well-studied and verified variations known to have an effect on your body functions and disease mentioned above.
This is the same process which is followed by 23andme and AncestryDNA companies not only for the MTHFR gene but hundreds of other genes of importance to your health.
How common is the MTHFR polymorphism?
There are several MTHFR mutations that have been associated with different conditions like increased homocysteine levels and neural tube defects. However, the two common and widely known polymorphisms in MTHFR are C677T (Alanine replaces Valine at the 222nd position of the amino acid sequence) and A1298C (Glutamate replaces Alanine at the 429th position of the amino acid sequence). C677T being more common of the two.
About ten percent of the North American population is T-homozygous for this polymorphism, which means both strands of their DNA have the T base. There is ethnic variability in the frequency of the T allele.
Frequency in Mediterranean/Hispanic population is greater than the frequency in Caucasians which, in turn, is greater than in Africans/African-Americans.
Why should I test for my MTHFR gene status?
As mentioned earlier, MTHFR is one of the very important enzymes with implications to your health and disease risk. Importantly, you can make simple modifications to your diet to reverse the effects of MTHFR deficiency. Hence, learning about your MTHFR status empowers you to take preventive action against possible detrimental effects of the enzyme deficiency.
23andme MTHFR and the v5 chip
The v5 chip from 23andme screens for approximately 6,50,000 SNPs. Both the important well-studied MTHFR polymorphisms, C677T (rs1801133) and A1298C (rs1801131) are there in this new version.
Besides the v5 chip, v4 and v3 chips also cover the prominent MTHFR SNPs. A variety of other ancestry data providers such as 23andme, Ancestry DNA, and others also test for the MTHFR SNPs.
When should I test for my MTHFR gene status?
You should consider getting your MTHFR gene evaluated if you have a family history of neural tube defects, homocystinuria or for knowing the response to drugs like methotrexate (a commonly used chemotherapeutic drug for certain types of leukemias).
In general, its good for everyone to know their MTHFR status. MTHFR deficiency can be easily addressed through simple dietary modifications. This can have significant health benefits for the individual.
Checking your DNA raw data for MTHFR status.
The MTHFR nucleotide at position 677 in the gene has two possibilities: C (cytosine) or T (Thymine). C at position 677 (leading to the alanine amino acid at the 222nd position) is the normal allele.
The 677T allele (leading to a valine substitution at the 222nd position) encodes a thermolabile enzyme with reduced activity since it is easily destroyed by heat.
Individuals with two copies of 677C (677CC) have the most common genotype. 677TT individuals (homozygous) have lower MTHFR activity than CC or CT (heterozygous) individuals.
The degree of enzyme thermolability is much greater in 677TT individuals (18–22%) compared with 677CT (56%) and 677CC (66–67%). Individuals of 677TT are predisposed to mild hyperhomocysteinemia (high blood homocysteine levels) because they have less active MTHFR available to produce 5-methyltetrahydrofolate (which is used to decrease homocysteine).
Low dietary intake of the vitamin folic acid can also cause mild hyperhomocysteinemia.
Essentially, your 23andme MTHFR analysis provider will be able to tell you whether your MTHFR enzyme efficiency is normal, reduced or severely reduced and recommend supplements or diets accordingly. With simple dietary modifications, you will be able to mitigate the enzyme deficiency.
Who tests for MTHFR mutations?
There are many service providers and online tools, that help you deduce your 23andme MTHFR status. Some of them are listed below:
- Xcode Life– Almost 40 SNPs related to methylation and MTHFR for a nominal fee. You can upload raw data from most major ancestry companies such as 23andme, Ancestry DNA, Family Tree DNA (FTDNA) and others, (view the complete list here) and learn about your 23andme MTHFR status. The reports come with a detailed set of recommendations which guide you through the dietary changes necessary to mitigate the enzyme deficiency.
- Genetic genie– is a tool that accepts raw data only from 23andme
- Genetic life hacks blog– It is not a tool but has a lot of information dedicated to methylation and the MTHFR gene that you can use as a reference if you have your raw data and a little knowledge about how SNPs work. However, if you do not have such a background do not attempt to interpret the information all by yourself.
- Dr. Amy Yasko’s Nutrigenomic testing
Where do I start?
If you already have your DNA raw data from any ancestry test you may have done, you can easily find out your 23andme MTHFR status from your Ancestry or 23andme data. Otherwise, you may consider another ancestry test for $99 or less, so that you can get your genetic raw data for further analysis. Once you have your 23andme raw data, you can upload to xcode.life for your 23andme MTHFR status report.
How to learn about your MTHFR status now?
If you have your 23andme or other Ancestry DNA test data, you can easily learn about your 23andme MTHFR status by uploading your data to Xcode.in. Specialized laboratories such as LabCorp and others will be able to perform this test for you for a fee, but this is expensive and mostly unnecessary. Most ancestry DNA providers include the prominent MTHFR mutations in their raw data. You can order a 23andme ancestry test, to learn a lot more about your health than just ancestry, including your MTHFR status.