Also known as: JAK2 Gene Test« Back to test list
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 PV, ET or 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.
This test is usually requested by a haematologist or oncologist.
4-10 mL of bone marrow in dedicated EDTA or 10 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 also recommend that the patient or another adult check the labelling of request forms and sample tubes.