Special Instructions
Please provide indications for JAK2 testing and specimen type. Direct any questions regarding this test to customer service at 800-345-4363.
Expected Turnaround Time
5 - 7 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Information
Related Documents
Specimen Requirements
Specimen
Whole blood, bone marrow or cell pellet
Volume
3 to 5 mL whole blood or 1 to 2 mL bone marrow
Minimum Volume
3 mL whole blood or 1 mL bone marrow
Container
Lavender-top (EDTA) tube, green-top (sodium heparin) tube, tan-top (K2-EDTA) tube or pink-top (K2-EDTA) tube
Collection
Submit at room temperature. Specimen should arrive at the testing laboratory within 48 hours of collection. Indicate the date and time of collection on the test request form.
Storage Instructions
Ship at room temperature. If specimen is to be stored prior to shipment, store at 2°C to 8°C.
Causes for Rejection
Specimen does not meet collection criteria; frozen whole blood, marrow, or cell pellet; leaking tube; clotted blood or marrow; grossly hemolyzed specimen or otherwise visibly degraded; contamination by another specimen; specimens containing suspicious foreign material.
Test Details
Use
The quantitative real-time PCR assay detects V617F mutation (c.1849 G>T) observed in approximately 95% polycythemia vera (pv), 55% essential thrombocythemia (ET), and 55% primary myelofibrosis (PMF). It is also infrequently present (3% to 5%) in myelodysplastic syndrome, chronic myelomonocytic leukemia, and other atypical chronic myeloid disorders. The results should be interpreted in the context of all clinical and laboratory findings. No therapeutic action should be taken based solely on these results.
Limitations
This assay detects only the JAK2V617F point mutation. Other mutations that may occur in the JAK2 gene will not be detected. In vitro studies have indicated that this assay has an analytical sensitivity of 1%. This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Methodology
Total genomic DNA was extracted and subjected to TaqMan® real-time PCR amplification/detection. Two amplification products per sample were monitored by real-time PCR using primers/probes specific to JAK2 wild type (WT) and JAK2 mutant V617F. The ABI7900 Absolute Quantitation software will compare the patient specimen values to the standard curves and generate percent values for wild type and mutant type. The numerical values of sample Mutant Quantity/(Sample Mutant Quantity + Sample Wild Type Quantity) X100 is reported as a percentage.
References
Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet. 2005 Mar 19-25; 365(9464):1054-1061. Erratum: Lancet. 2005 Jul 9-15;366(9480):122. 15781101
James C, Ugo V, Le Couédic JP. A unique clonal JAK2 mutation leading to constitutive signaling causes polycythaemia vera. Nature. 2005 Apr 28; 434(7037):1144-1148. 15793561
Kralovics R, Passamonti F, Buser AS, et al. A gain-of-function mutation of JAK2 in myeloproliferative disorders. N Engl J Med. 2005 Apr 28; 352(17):1779-1790. 15858187
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 481020 | JAK2 V617F, Quantitative | 481021 | JAK2 V617F Mutation Quant Rslt | 43399-5 | ||
| 481020 | JAK2 V617F, Quantitative | 481026 | Quantitative Value: | % | 53761-3 | |
| 481020 | JAK2 V617F, Quantitative | 480998 | Background: | 77202-0 | ||
| 481020 | JAK2 V617F, Quantitative | 480999 | Methodology: | 49549-9 | ||
| 481020 | JAK2 V617F, Quantitative | 481016 | References: | 75608-0 | ||
| 481020 | JAK2 V617F, Quantitative | 481132 | Director Review: | 72486-4 |
© 2021 Laboratory Corporation of America® Holdings and Lexi-Comp Inc. All Rights Reserved.
CPT Statement/Profile Statement
The LOINC® codes are copyright © 1994-2021, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. Permission is granted in perpetuity, without payment of license fees or royalties, to use, copy, or distribute the LOINC® codes for any commercial or non-commercial purpose, subject to the terms under the license agreement found at https://loinc.org/license/. Additional information regarding LOINC® codes can be found at LOINC.org, including the LOINC Manual, which can be downloaded at LOINC.org/downloads/files/LOINCManual.pdf