The MTHFR gene is a gene that codes for an enzyme (protein) called methylenetetrahydrofolate reductase. This enzyme is essential for several biochemical reactions in the human body, with its key function being in the conversion of folate to methylfolate.
Folate and Methylation
Folate, known more commonly as vitamin B9, is a crucial nutrient for blood cell production, growth, and development. However, it can only perform these functions if the MTHFR enzyme successfully converts it into its active form, methylfolate.
Methylation is a first-line (stage one) biochemical process that involves adding a methyl group onto a molecule to convert it into its active form. It’s also required to modify gene expression and turn genes on or off.
Methylation is important in DNA synthesis, DNA repair, and amino acid breakdown. It’s also vital for embryonic development as it enables certain genes to be activated or deactivated inside a growing embryo, which is essential for cell differentiation (where stem cells become specialized cells, such as skin cells, muscle tissue, or endothelial cells).
Can the MTHFR Gene Mutate, and What Happens if it Does?
The short answer is, yes, the MTHFR gene can mutate, as can any gene in your DNA. When there is an MTHFR gene mutation, it can impact the resulting enzyme’s structure and function.
The methylenetetrahydrofolate reductase protein produced by a mutated MTHFR gene may be deficient in key areas. As a result, this protein can’t perform its methylation functions effectively, and many important compounds might remain unmethylated and inactive.
Reduced methylfolate and neurotransmitters
There are several MTHFR gene variants, with the two most studied being C677T and A1298C. These mutated gene variations can lead to reduced enzyme activity and function, reducing the conversion of folate (inactive) into methylfolate (active).
With less methylfolate, the body produces less serotonin, dopamine, and norepinephrine (noradrenaline). Reduced neurotransmitters in the brain can interfere with mood and may increase the risk of anxiety, depression, and mood disorders.
Higher homocysteine
Homocysteine is an amino acid that the body converts into various other compounds.
Certain mutations in the MTHFR gene have been linked to higher homocysteine levels. Although an important amino acid, too-high levels of homocysteine can lead to an increased risk of atherosclerosis, high blood pressure, and cardiovascular disease.
Changes in gene expression
As the MTHFR gene codes for an enzyme involved in methylating DNA, mutations in the gene (and the resulting enzyme) can impact the expression of DNA. Gene expression (or DNA expression) refers to whether a gene is on (expressed) or off (not expressed). A gene that is expressed will be transcribed into a protein.
Methylation is the process that causes a gene to be on or off. The methylenetetrahydrofolate reductase enzyme methylates certain parts of genes to change whether they get expressed or not. However, if the MTHFR gene and the enzyme it produces are mutated, the enzyme might be unable to influence gene expression as it normally should.
Changes in gene expression can have widespread effects on the body and can be detrimental to you in some cases. Disrupted gene expression is linked to a range of chronic conditions, including many cancers.
Reduced fetal development during pregnancy
Many supplements are recommended for a healthy pregnancy. In particular, folate is essential for fetal growth and development during pregnancy, which is why pregnant women are recommended to take daily folic acid supplements.
Folate supplementation is particularly during the first 12 weeks of pregnancy (the first trimester) when embryonic development and fetal growth occur at rapid rates. Daily folate reduces the risk of neural tube defects in the developing fetus.
However, pregnant women with a mutated MTHFR gene may be at a higher risk of experiencing miscarriage and pre-eclampsia or having a baby with birth defects, such as spina bifida, or a low birth weight.
Reduced detoxification abilities
Individuals with a non-mutated MTHFR gene can produce enzymes necessary for removing toxins from the body and reducing the risk of diseases. These enzymes methylate compounds like environmental toxins, heavy metals, and drug metabolites, which tags them for breakdown and removal.
However, a protein produced from a mutated MTHFR may not tag compounds for detoxification, meaning they remain in the body, where they can accumulate and cause several issues. High toxin concentrations in the body can increase the risk of chronic diseases and may impact the function of other important biochemical pathways.