Genetics
Assesing thrombosis risk by genetic testing
Deep vein thrombosis (blood clots in the veins) is a common disorder, one in ten persons is affected. Clots form primarily in the large veins of the lower limbs, and the clot may block the path of the blood flow. If a clot breaks away and is carried by the bloodstream, it may lodge in the lungs, the brain or other organs (embolism), which have severe consequences.
Who are at risk?
- use of contraceptive pills
- pregnancy
- smoking
- prolonged bedrest
- major operations
- trauma
- malignant tumours
Particularly, the women of childbearing potential are at risk since the use of contraceptive pills, pregnancy and delivery significantly increase the risk of thrombosis. This is associated with the anticoagulant effect of female sex hormones. This effect is also seen in case of treatment with female sex hormones to promote conception, prevent breast cancer or alleviate menopausal symptoms.
In addition, the development of deep vein thrombosis is facilitated by prolonged bedrest, major operations, trauma, malignant tumours or smoking.
Women who carry this genetic disorder may only start taking hormonal contraception after careful consideration of the advantages and disadvantages and only under close control.
In some cases your doctor may recommend prophylactic anticoagulant treatment, change in your lifestyle, frequent vein monitoring and inform you in the early symptoms of thrombosis. There will be opportunity to test the close relatives since the mutation is inherited from our parents and may be transferred to our children.
How can it be detected?
An oral mucosal swab taking several seconds without any discomforts is appropriate or the sample taken during gynaecological test.
There can be three types of test result:
- no change (negative result),
- mutation occurs in one of the two copies of the gene (positive results)
- Leiden mutation is detected on both copies of the gene (positive results)
This result is for the life and does not need to be repeated. The so called APC resistance phenomenon detectable by laboratory testing of coagulation is caused mainly by Leiden mutation.