MTHFR Gene Test (Folate deficiency & High homocysteine levels)

High blood levels of an amino acid called homocysteine is recognized as a risk factor for coronary artery disease, abnormal blood clotting in the veins (venous thrombosis) and stroke.

High homocysteine levels in the blood have also been associated with neural tube defects, stillbirths and recurrent pregnancy loss. The major cause of high homocysteine levels is folate deficiency. Other factors include insufficient vitamin B12 and genetic mutations in the MTHFR gene.

The MTHFR gene, technically called Methylenetetrahydrofolate Reductase, is a key enzyme required to metabolise homocysteine. The most common mutation in MTHFR is called C677T. People with two copies of this mutation (i.e. one inherited from their mother and one from their father) are called homozygotes, and are found in 5 - 10% of the population. These individuals are predisposed to developing high blood levels of homocysteine, particularly when their diets are low in folate.

A second mutation in the MTHFR gene, called A1298C, has also been implicated with high levels of homocysteine when found together with the C677T mutation.

MTHFR gene mutations found in individuals with other inherited clotting genes (such as Factor V Leiden) have a dramatically increased risk of venous thrombosis.