JAK2V617F Mutation Analysis, Quantitative, With Reflex to JAK2 Exon 12-15 Mutation Analysis by NGS
CPT:
81270
Expected Turnaround Time
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.
Specimen Requirements
Specimen
Whole blood or bone marrow
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, yellow-top (ACD) tube, tan-top (K2-EDTA) tube or pink-top (K2-EDTA) tube
Collection
Submit at room temperature. Specimens should arrive in the laboratory within 48 hours of collection. Indicate date and time of collection on 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 all of the criteria for sample type, container, minimum volume, collection and storage; frozen whole blood or marrow; leaking tube; clotted blood or marrow; grossly hemolyzed or otherwise visibly degraded; contamination by another specimen; specimen containing foreign material
Test Details
Use
Molecular testing of blood or bone marrow is useful in the evaluation of suspected myeloproliferative neoplasms (MPN). This test will assess for the JAK2V617F (exon 14) mutation first and will reflex JAK2 exon 12 to 15 mutation analysis if the JAK2V617F mutation is negative.
The JAK2 (Janus kinase 2) gene encodes for a non-receptor protein tyrosine kinase that activates cytokine and growth factor signaling. The V617F (c.1849 G>T) mutation results in constitutive activation of JAK2 and downstream STAT5 and ERK signaling. The V617F mutation is observed in approximately 95% of polycythemia vera (PV), 60% of essential thrombocythemia (ET) and primary myelofibrosismia (PMF). It is also infrequently present (3-5%) in myelodysplastic syndrome, chronic myelomonocytic leukemia and other atypical chronic myeloid disorders. A small percentage of JAK2 mutation-positive patients (3.3%) contain other non-V617F mutations within exons 12 to 15. In particular, mutations in exon 12 of JAK2 have been described in approximately 3% of patients with PV. JAK2 mutation allele of mutant allele characterized by thrombocytosis, intermediate levels with erythrocytosis and high mutant allele burden, correlating with enhanced myelopoiesis of the BM, leukocytosis, increasing spleen size and circulating CD34-positive cells.
Limitations
This assay has a sensitivity of approximately 1% VAF for JAK2V617F and 2.5% VAF for other mutations in JAK2 exons 12 to 15. Deletions in JAK2 up to 6 bp and insertions up to 34 bp have been detected in validation studies.
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
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This assay has a sensitivity of approximately 1% VAF for JAK2V617F and 2.5% VAF for other mutations in JAK2 exons 12 to 15. This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration. |
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This assay has a sensitivity of approximately 1% VAF for JAK2V617F and 2.5% VAF for other mutations in JAK2 exons 12 to 15. Deletions in JAK2 up to 6 bp and insertions up to 34 bp have been detected in validation studies. 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
Amplicon-based Next Generation Sequencing
References
Alghasham N, Alnouri Y, Abalkhail H, Khalil S. Detection of mutations in JAK2 exons 12-15 by Sanger sequencing. Int J Lab Hematol. 2016 Feb;38(1):34-41.26361084
Arber DA, Orazi A, Hasserjian R, et al. The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood. 2016 May 19;127(20):2391-2405.27069254
Ma W, Kantarjian H, Zhang X, et al. Mutation profile of JAK2 transcripts in patients with chronic myeloproliferative neoplasias. J Mol Diagn. 2009 Jan;11(1):49-53.19074595
NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) Myeloproliferative Neoplasms Version 3.2022 - August 11, 2022.
Swerdlow SH, editor. WHO classification of Tumours of Haematopoietic and Lymphoid Tissues. 4th edn. Lyon, France: International Agency for Research on Cancer; 2017.
Tefferi A. Primary myelofibrosis: 2021 update on diagnosis, risk-stratification and management. Am J Hematol. 2021 Jan;96(1):145-162.33197049
Vainchenker W, Kralovics R. Genetic basis and molecular pathophysiology of classical myeloproliferative neoplasms. Blood. 2017 Feb 9;129(6):667-679.28028029
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