Prothrombin is a component of blood clotting. It is formed in the liver and converted by an activator into thrombin, which is relevant for blood clotting. Thrombin ensures that platelets are released and can form a wound closure (platelet aggregation).Furthermore, thrombin converts fibrinogen into fibrin, which is a component of a thrombus (blood clot).
In the case of a mutation of the genes that regulate factor II (prothrombin mutation G20210A), there is too much prothrombin in the blood.
About 2% of the population in Europe is affected by such a mutation. If this mutation is inherited from only one parent (heterozygous), the risk of deep venous thrombosis (DVT) increases 3-fold compared to people without the mutation. That the mutation is inherited from both parents (homozygous) has occurred only rarely.Pregnant women with a factor II mutation even have a 15-fold increased risk of thrombosis.
The procedure
Material needed
- EDTA blood (a completely filled tube).
Preparation of the patient
- Not necessary
Disruptive factors
- The analysis should be done within a few hours (otherwise freeze).
Normal value
| Prothrombin %. | 70-100 |
Indications (areas of application)
- Suspicion of increased thrombosis tendency (thrombophilia screening).
- Fresh thrombosis
- Thrombosis at a young age
- Two months after thrombosis
- Thrombosis in an unusual part of the body (e.g., eye)
- Before hormonal contraception (contraception).
- Before pregnancy or after an abortion (miscarriage).
Interpretation
Interpretation of increased values
- Thrombophilia
Interpretation of decreased values
- Liver dysfunction
Other indications
- Insufficient factor II function may also be due to acquired causes such as therapy with anticoagulants (anticoagulant drugs), pregnancy, use of hormonal contraceptives (“the pill”), or liver disease.