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Prothrombin
Scientific background:
Summary: Mutations that cause dysfuntion result in bleeding disorders, whereas a single genetic variation outside the coding region is associated with increased risk of thrombosis.
Gene: The gene of Prothrombin or coagulation factor 2 (F2) is localized on chromosome 11 (11p11-q12). It is about 21kb in size and consists of 14 exons.
Pathology: There is a mutation in the prothrombin gene G20210A that causes hypercoagulability. It is not known yet what the mechanism is.
Pathophysiology: Prothrombin also called coagulation factor II cleaves in its active form (thrombin) fibrinogen and hereby forms fibrin the final product of the coagulation process. But thrombin is not only essential for coagulation it has a function in interrupting of the coagulation process.
Clinical signs: Patient with this mutation have a higher risk for thrombosis. These occur in atypical localizations for example in central ocular vein.
Epidemiology: The prevalence of this mutation is about 2,5%. In the South of Europe it is twice as high as in the North. In Africa und Asia this mutation is rather rare.
Interpretation: The relative Risk for Thrombosis is 2-3.
Test strategy: Patients with clinical evidence of thrombophilia. Family screening if a family member is a carrier.
Methodology:
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clinical
test |
Method |
Fragment analysis |
| Turn-around time |
5 working days |
| Effort |
little |
| Specimen |
DNA |
| Quality assessment |
Full external quality control |
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Only the target mutation is detected all other genetic variations, though possibly important they may be, are missed. |
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