Also known as: Prothrombin Gene Mutation« Back to test list
A specific mutation in the prothrombin gene (F2) places a person at increased risk of venous thrombosis. This predisposition in inherited as an autosomal dominant disorder.
The presence of one mutated F2 gene increases the risk of venous thrombosis by 2-5-fold. There is dispute regarding the clinical utility of this information in an unaffected patient, or in the management of an affected patient. The presence of two mutated F2 genes is associated with much higher risk of venous thrombosis; the recurrence risk is presumably increased as well.
This is an assay for heritable mutations. It may raise issues of ethics or consent that are different from most other investigations ordered in the routine care of a patient. The interpretation of the result may also be dependent on the family history and the interpretation of other studies.
Analysis of F2 gene for the 20210G>A (c.*97G>A) variant.
This test can be requested by any medical practitioner.
4 mL blood in EDTA (separate tube required). Specimens may be collected by the requesting practitioner or at any Sonic Healthcare pathology collection centre.
To help ensure the quality of the test, a genetic test should be done with a dedicated sample whenever possible i.e. a sample collected specifically for that test rather than a sample that is used for multiple tests.
We also recommend that the patient or another adult check the labelling of request forms and sample tubes.
Consider other genetic risk factors for thrombosis (Factor V Leiden).