Use of test
A specific acquired variant in the JAK2 gene (p.Val617Phe, or V617F) is common in certain myeloproliferative neoplasms. It is present in 95% of patients with polycythemia vera (PV), and approximately 50% of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). This test can assist in making the diagnosis of these disorders.
The presence of this mutation provides strong evidence for polycythaemia vera (PV), essential thrombocytosis (ET) or primary myelofibrosis (PMF).
The absence of this mutation makes it unlikely that the patient has PV, but the diagnosis has not been excluded. The absence of this mutation does not exclude diagnoses of ET or PMF.
This is an assay for non-heritable mutations. It does not raise issues of ethics or consent that are different from most other investigations ordered in the routine care of a patient.
Analysis of the sequence of the JAK2 gene for the presence of V617F.
Requesting the test
This test is usually requested by a haematologist or oncologist.
1.0 mL of bone marrow in dedicated EDTA or 4 mL peripheral blood in dedicated EDTA
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.
7-10 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 73325.