The MTHFR gene has two important roles in the body. One role is adding methyl groups to DNA to control gene expression. This can either strengthen or block access to gene-coding DNA segments. This is known as epigenetics. The second role of the MTHFR gene is in folate metabolism. Folate helps convert the amino acid homocysteine back to another essential amino acid called methionine.
MTHFR has a common variant linked to hyperhomocysteinemia.
In 1995, scientists discovered a variant in the MTHFR gene, known as C677T. This variant is the most widely studied and globally found mutation in MTHFR. People with this variant can have high levels of homocysteine and develop a condition called hyperhomocysteinemia. Folate can stabilise the MTHFR protein and restore homocysteine levels to normal. In fact, taking a daily supplement of low-dose folic acid treats hyperhomocysteinemia.
Symptoms you might notice if you have hyperhomocysteinemia:
- Mental deterioration: loss of previously present mental abilities in adults.
- Muscle weakness.
- Paresthesia: abnormal sensations such as tingling, pricking, or numbness of the skin with no apparent physical cause.
- Ataxia: lack of coordination between muscles, limbs and joints; lack of ability to judge distances that can lead to under- or overshoot in grasping movements; inability to perform rapid movements requiring antagonising muscle groups to be switched on and off repeatedly.
- Gait disturbance: any disruption of the ability to walk.
- Seizure.
- Risk for stroke: sudden impairment of blood flow to a part of the brain because of occlusion or rupture of an artery to the brain.
- Risk for coronary artery disease: reduction of the diameter of the coronary arteries as the result of an accumulation of atheromatous plaques within the walls of the coronary arteries.
Symptoms occasionally linked to hyperhomocysteinemia:
Cognitive impairment; headaches; impairment of certain skills like reading or attention that interfere with the ability to learn; lethargy; loss of strength in arms or legs on one side of the body (hemiparesis); psychosis; formation of a blot clot in a deep vein (deep venous thrombosis); stroke that occurs because of thromboembolism; apnea.
C677T still raises your risk for heart problems.
Scientists have found that the C677T variant raises your chances of getting cardiovascular disease by 15%. However, more recent studies show that taking folate supplements does not effectively reduce these risks. That’s why it’s still useful to know your MTHFR gene status—it can help you understand your risk of heart problems.
MTHFR has a common variant linked to autism risk.
Recently, scientists calculated that the C677T variant raises your current risk of autism spectrum disorder by 50%. If your current risk is high, this can make a substantial impact. Scientists think genes like MTHFR might be why some people with similar genetics have different levels of autism risk, since methylation changes are more affected by the environment than your genes. That’s why people with the same genetics may have different diagnoses.
It is important to remember:
- Doctors often diagnose hyperhomocysteinemia by checking plasma levels of homocysteine and folate.
- Folate supplements cure many hyperhomocysteinemia symptoms, but not cardiovascular risks.
- A balanced diet rich in folate and essential nutrients is crucial for overall health.
