Diagnostic Use
This assay detects the acquired JAK2 c.1849G>T (p.Val617Phe; V617F) variant. The JAK2 V617F variant is a common molecular marker of myeloproliferative neoplasms (MPNs), occurring in approximately 97% of patients with polycythaemia vera (PV), 57% of patients with essential thrombocythaemia (ET), and 50% of patients with primary myelofibrosis (PMF) [1].
For the diagnostic evaluation of suspected MPN, allele-specific PCR (AS-PCR) is performed as the first-line test. This test may be requested by general practitioners and specialist clinicians.
Samples with a positive or equivocal result by AS-PCR undergo reflex testing by droplet digital PCR (ddPCR) to confirm the presence of the variant and determine the variant allele fraction (VAF). Refer to the Interpretation section for further details. Samples with no JAK2 V617F variant detected by AS-PCR do not undergo further testing.
Quantitative assessment of JAK2 V617F by ddPCR is also available for selected patients following allogeneic bone marrow transplantation or during therapy, where molecular monitoring is clinically indicated. This testing is available only on request by a haematologist.
References
- Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet. 2005;365:1054-1061.
Test Method
Detection of NM_004972.4:c.1849G>T, p.(Val617Phe) is determined by
allele-specific PCR. The sensitivity of this assay is approximately 1-2%. The results and interpretations assume that the samples received by
the laboratory are correctly identified and that the clinical diagnosis is as
stated.