I. Disease
Thrombophilia or thromboembolic disease describes clinical situations where venous thromboses (early, recurrent or unusual location), are observed, associated to a biological test in hypercoagulability.
II. Causes/risk
This disease is a very frequent/common disease.Risk factors include:
- Acquired risk factors (medication, immobility, cancer pathology, obesity, varicose veins, etc),
- Genetic factors.
The risk factors are additive.
III. Epidemiology
It is estimated that the frequency of thromboembolic disease is around 1/1000 per year. There is no major difference in the expression of the disease depending on the gender.
IV. Mutations
The main mutations are found in the genes of FACTOR II (Prothrombine), FACTOR V and MTHFR (methylenetetrahydrofolate reductase).The most common is the mutation of FACTOR V or Leiden mutation, which is found in 20 to 30 % of patients presenting a Thromboembolic diseaseFollowed by the Leiden mutation of FACTOR V, which is present in 8 to 10% of patients. The thermolabile variant of the MTHFR is due to the mutation C677T, very frequent in the general population. In the homocygotic stade, mutations in this key enzyme in homocysteinemetabolism, contribute/provokes to hyperhomocysteinemia, which is a risk factor of venous thrombosis. Depending on the genotype of the patient, the disease will manifest itself in a more or less severe way, and early or late stage.Thrombophilia has been linked to both recurrent miscarriage and possibly various complications of pregnancy such as intrauterine growth restriction, stillbirth, severe pre-eclampsia and abruptio placentae.[2]
V. Genetic analysis – Technique
Biological sample: saliva on FTA cardAnalysis of the following mutations:
- Factor II Leiden (mutation 20210G>A)
- Factor V Leiden (mutation R506Q)
- Gene MTHFR (mutation 677C>T)
Analysis description: Real time PCR (TaqMan) allelic discrimination
VI. Treatment
There is no specific treatment for most thrombophilias, but recurrent episodes of thrombosis may be an indication for long-term preventative anticoagulation