Note: All samples should be forwarded to LabPlus at room temperature within 24hours.
Limit of detection for quantitative testing is a VAF (variant allele fraction) of 0.1% for diagnostic samples (single well).
Limit of detection for minimal residual disease (MRD) monitoring is a VAF of 0.01%. (triplicate well).
All quantitative results have a MU of <3% VAF.
JAK2 ddPCR
Effective 26/04/2022
This is a test for the JAK2 V617F acquired variant.
This variant is a common feature of myeloproliferative neoplasms (MPN) and has been reported to be present in around 97% of polycythaemia vera (PV), in around 57% of essential thrombocythaemia (ET) and in around 50% of primary myelofibrosis (PMF) cases [1].
For diagnostic testing of JAK2 in work up of a possible MPN, allele-specific PCR (AS-PCR) testing is used as first line testing. This test is available for GPs and specialists to order. Samples which give a positive or equivocal result on AS-PCR will undergo cascade testing via ddPCR, to enable a quantitative assessment of the variant allelic fraction (VAF) of JAK2 V617F. Please see interpretation notes for further details. Samples with no JAK2 V617F detected on AS-PCR will not have further testing initiated. Where JAK2 V617F testing is negative but a high suspicion of ET/PMF remains consider CALR/MPL testing. [2]
JAK2 quantitative assessment via ddPCR is also available to selected patients post bone marrow transplant or after introduction of therapy, for monitoring purposes. This testing is only available when ordered by a haematologist.
[1] Baxter et al., Lancet 2005; 365: 1054-1061.
[2] Klamfl et al. (2013) NEJM, 369(25):2379-2390
To contact the Molecular Haematology team please call:
| Auckland City Hospital | (09) 307 4949 |
| Lablink | ext 22000 |
| Prof. Peter Browett (Haematologist) | ext 9090-86281 |
| Dr. Imogen Caldwell (Haematologist) | ext 22006 |
| Nikhil Ghallayan (Section Leader) | ext 22005 |
| Molecular Haematology Office | ext 22005 |
For more information about the Molecular Haematology service at LabPLUS: