MTHFR (C677T) genetic test
While the laboratory test for predisposition to thrombosis (thrombophilia) examines congenital and acquired coagulation disorders, the MTHFR (C677T) genetic test helps screen for genetic predisposition to arterial and venous thrombosis, thereby contributing not only to improving an individual’s health, but the risk of foetal death in pregnancy can also be avoided.
The assay is suitable for detecting a mutation in the MTHFR gene.
What is thrombosis?
Thrombosis is a disease in which a blood clot (thrombus) forms in the veins, which can partially or completely block the blood flow. The formation of blood clots is caused by a coagulation disorder.
Blood clots can form in different areas of the circulatory system, but are most often formed in the deep veins, typically in the lower limbs, as blood circulation can slow down more easily here. A blood clot can also form in the upper veins, but this is mostly harmless and easy to treat.
If the resulting blood clot is loosely attached to the vessel wall, it can easily come off and the detached blood clot (embolus) will start to drift with the bloodstream. A detached blood clot causes a serious problem when it arrives at a narrower blood vessel section and becomes wedged in and blocks the blood flow. This is when an embolism develops. Blood clots detached from the veins of the legs usually pass through the heart and block one or more arteries in the lungs, causing pulmonary embolism.
It is important to take the symptoms of thrombosis seriously so that major trouble can be prevented and avoided. The most common symptoms are a swollen, red, touch-sensitive, warm limb, which most often occurs around the foot, ankle, or thigh. Swelling is caused by fluid build-up (oedema), which can lead to ulcers later if left untreated. If you experience symptoms, visit an emergency room as soon as possible.
Why is a mutation in the MTHFR gene a threat?
Elevated MTHFR gene concentrations as an independent factor increase the risk of developing ischemic heart disease, cerebrovascular disease, peripheral arteriosclerosis, deep vein thrombosis, and foetal neural tube defect disorder.
Due to the nutritional factor, it develops when the body’s supply of folic acid is not abundant enough (for example, many folic acids are contained in “leafy” vegetables: sorrel, spinach, lettuce).
It can develop as a result of inherited factors. The most common of the inherited factors are point mutations in the methylene tetrahydrofolate reductase (MTHFR) enzyme gene (C677T and A1298C). Inherited factors even include the FV Leiden mutation, a coagulation disorder of genetic origin. If a mutation in the MTHFR gene co-occurs with a FV Leiden mutation, we can talk about a higher risk factor.
A moderate increase in the level of the MTHFR gene occurs in 5-10% of the population, at which point the risk of thrombosis is almost 3 times the normal value. Tests should be performed as part of a thrombosis examination.
When is the test recommended?
- recurrent venous thromboembolism (VTE),
- in case of first VTE:
- if the thrombotic event occurs in a relatively young person (under 50 years of age),
- without cause, at any age,
- or it is in an unusual place, such as in the blood vessels of the upper arm, brain, or abdominal organs,
- during pregnancy, post-partum, contraceptive and hormone replacement therapy,
- loss of two or more foetuses.
The test can also be performed on an asymptomatic family member with a known thrombophilic family.
Who should have the test done?
- Hereditary predisposition to thrombosis is highlighted by the following:
- Thrombosis at an early age that cannot be explained and/or recurrent.
- Venous thrombosis under 50 years of age.
- Venous thrombosis during pregnancy or the use of contraception.
- Certain cases of recurrent miscarriage or unexpected obstetric complications.
- Abnormal APC resistance test result.
- If thrombosis had occurred in the family, as well as if a family member is a confirmed Leiden carrier.
How do I prepare for the test?
Do not eat, drink, chew or smoke for 2 hours before the test.
When is the result expected?
On the 12th working day following the examination.