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Prothrombin gene

Also known as: Prothrombin gene mutation, F2, thrombophilia

Test category:

Familial - Haematological; Reproductive - Miscarriage

Use of test


A specific mutation in the prothrombin gene (F2) places a person at increased risk of venous thrombosis. This predisposition is 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.

Ethical considerations:

This is an assay for heritable variants which can alter the probability that a person will develop a disorder. The test result is not, in isolation, diagnostic of a disease and the test result is not necessarily clinically significant for the patient's relatives.


Analysis of F2 gene for the 20210G>A (c.*97G>A) variant.

Requesting the test


This test can be requested by any medical practitioner.

Sample required:

4 mL blood in EDTA (separate tube required). Specimens may be collected by the requesting practitioner or at any Sonic Healthcare collection centre (see link below).

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 recommend that the patient or another adult check the labelling of request forms and sample tubes.

>Link to Sonic Healthcare collection centres

Special instructions:

Consider tests for other genetic risk factors for thrombosis such as Factor V Leiden.

Turnaround time:

5 business days.


This test has a Medicare rebate which, subject to the requirements of the Medicare descriptor being met, may cover all or part of the cost.


The Medicare details, including descriptor and schedule fee, are listed under MBS item 73308.

Click here for our billing policy.