Test Id : JAKFM
JAK2 V617F Mutation Detection, Bone Marrow
Useful For
Suggests clinical disorders or settings where the test may be helpful
Diagnosis or differential diagnosis of myeloproliferative disorders by JAK2 V617F variant detection in bone marrow specimens
Method Name
A short description of the method used to perform the test
Quantitative Polymerase Chain Reaction (qPCR)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Janus kinase 2 gene
Tyrosine Kinase Mutation
JAK2
V617F
MPN
Specimen Type
Describes the specimen type validated for testing
Bone Marrow
Shipping Instructions
Specimen must arrive within 7 days of collection.
Necessary Information
The following information is required:
1. Pertinent clinical history
2. Clinical or morphologic suspicion
3. Date of collection
4. Specimen source
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Container/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Send bone marrow specimen in original tube. Do not aliquot.
3. Label specimen as bone marrow.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
1 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Moderately to severely clotted | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Bone Marrow | Ambient (preferred) | 7 days | |
| Refrigerated | 7 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Diagnosis or differential diagnosis of myeloproliferative disorders by JAK2 V617F variant detection in bone marrow specimens
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Mutations in the JAK2, CALR, and MPL genes are considered driver events in the BCR::ABL1 negative myeloproliferative neoplasms (MPN), including polycythemia vera (PV), primary myelofibrosis (PMF) and essential thrombocythemia (ET). The JAK2 V617F mutation occurs in 95% to 98% of patients with PV, 50% to 60% of patients with PMF and 50% to 60% of patients with ET respectively at diagnosis. Other JAK2 mutations in exons 12 through 15 occur in the remaining patients with PV. Mutations in the CALR gene occur in 20% to 30% of patients with PMF and 20% to 30% of patients with ET at diagnosis. A 52 base pair (bp) deletion (53%) and a 5 bp deletion (32%) are the most common mutations in the CALR gene while other types of mutations may occur in the remaining cases. MPL exon 10 mutations occur in 5% to 10% of patients with PMF and 5% to 10% of patients with ET. Mutations in JAK2, CALR, and MPL are mutually exclusive. The JAK2 V617F mutation is detected by quantitative polymerase chain reaction (qPCR). The CALR mutations are detected by PCR targeting exon 9. The MPL mutations in exon 10 are detected by Sanger sequencing. All mutations in JAK2, CALR, and MPL can also be detected by next-generation sequencing (NGS). In addition to the mutations in JAK2, CALR, and MPL, mutations in many other genes including ASXL1, TET2, DNMT3A, SRSF2, SF3B1, U2AF1, ZRSR2, EZH2, IDH1, IDH2, CBL, KRAS, NRAS, STAG2, and TP53 can occur in MPN. These additional mutations are more frequent in PMF and advanced disease, as compared to PV and ET. It is known that mutations in the ASXL1, SRSF2, U2AF1, EZH2, IDH1, and IDH2 are correlated with a poor prognostic risk. While a single gene test on JAK2, CALR, and MPL can be clinically useful, all above mentioned gene mutations can be detected by NGS.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Interpretation
Provides information to assist in interpretation of the test results
The results will be reported as 1 of the 2 states:
-Negative for JAK2 V617F variant
-Positive for JAK2 V617F variant
Positive variant status is highly suggestive of a myeloid neoplasm but must be correlated with clinical and other laboratory features for definitive diagnosis.
Negative variant status does not exclude the presence of a myeloproliferative neoplasm or other neoplasm.
Results below the laboratory cutoff for positivity have unclear clinical significance at this time.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
A positive result is not specific for a particular subtype of myeloproliferative neoplasm, and clinicopathologic correlation is necessary in all cases. If this test is ordered in the setting of erythrocytosis and suspicion of polycythemia vera, interpretation requires correlation with a concurrent or recent prior bone marrow evaluation.
A negative result does not exclude the presence of a myeloproliferative neoplasm or other neoplastic process.
In rare cases, a variant other than V617F may be present in an area that interferes with primer or probe binding, causing a false-negative result.
Supportive Data
Analytical sensitivity is determined at 0.06% (by dilution of a JAK2 V617F-positive cell line DNA into a negative cell line DNA).
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Klampfl T, Gisslinger H, Harutyunyan AS, et al. Somatic mutation of calreticulin in myeloproliferative neoplasms. N Engl J Med. 2013;369(25):2379-2390
2. Rumi E, Pietra D, Ferretti V, et al. JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood. 2014;123(10):1544-1551
3. Greenfield G, McMullin MF, Mils K. Molecular pathogenesis of the myeloproliferative neoplasms. J Hematol Oncol. 2021;14(1):103
4. Khoury JD, Solary E, Abla O, et al. The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Myeloid and Histiocytic/Dendritic Neoplasms. Leukemia. 2022;36(7):1703-1719
Method Description
Describes how the test is performed and provides a method-specific reference
Genomic DNA is extracted and 2 polymerase chain reactions (PCR) are performed. In each reaction, a short fragment of genomic DNA, including the variant site, is amplified using quantitative PCR in a real-time PCR instrument. In the first reaction, the 3' terminal base of the reverse primer matches the mutated sequence and the PCR conditions are such that it will only bind mutated DNA. In the second reaction, the 3' terminal base of the reverse primer matches the wild-type sequence and the PCR conditions are such that it will only bind the wild-type sequence. In both reactions, the PCR is monitored using TaqMan probe chemistry. The amount of mutated DNA and the amount of wild-type DNA is measured for each sample. In each run, the amount of mutated and wild-type DNA in a calibrator DNA sample is also measured. The calibrator is a mixture of DNA from a positive cell line (HEL) and a negative cell line (HL60) which is frozen in aliquots and expected to give an identical result in each run. Deviations in the calibrator result are assumed to be due to deviations in the run conditions and the sample results are corrected, accordingly. Following each reaction, Relative Quantification Software is used to calculate the mutated:wild-type ratio using the delta-delta Ct method, which is expressed as a unitless ratio following correction with the calibrator data.
The final result is reported as percent JAK2 V617F of total JAK2 (ie, [mutated/mutated + wild-type] x 100%), calculated from the relative quantification value.(Unpublished Mayo method)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
81270
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| JAKFM | JAK2 V617F Mutation, BM | 72333-8 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 618647 | JAK2 Result | 72333-8 |
| 618648 | Final Diagnosis | 69047-9 |
| 618649 | Method | 85069-3 |
| 618650 | Signing Pathologist | 18771-6 |
| 618652 | Additional Information | 48767-8 |
| 618653 | Disclaimer | 62364-5 |