Test Catalog

Test Id : PVJAK

Polycythemia Vera, JAK2 V617F with Reflex to JAK2 Exon 12-15, Sequencing for Erythrocytosis, Varies

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in the distinction between the myeloproliferative neoplasm polycythemia vera and other secondary erythrocytosis

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test Id Reporting Name Available Separately Always Performed
JAKXR JAK2 Exon 12-15 Sequencing, Reflex Yes, (order JAKXB-blood or JAKXM-bone marrow), Bill Only No

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Both DNA and RNA are extracted. The algorithm starts with a highly sensitive DNA-based JAK2 V617F test by allele specific polymerase chain reaction. If the JAK2 V617F result is negative or very low positive (0.06%-0.6%), JAK2 exon 12-15 Sanger sequencing will be performed on the stored RNA sample. If a JAK2 V617F mutation (>0.6%) is detected, no further testing will be performed.

 

The Sanger sequencing covers JAK2 exons 12 through the first 90% of exon 15, which spans the region containing essentially all mutations reported in myeloproliferative neoplasms. For more information, the following algorithms are available:

 

-Erythrocytosis Evaluation Testing Algorithm

-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation

-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

Allele-Specific Polymerase Chain Reaction (AS-PCR) and Sanger Sequencing

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

PV (JAK2 V617F, Exon 12-15) Reflex

Aliases
Lists additional common names for a test, as an aid in searching

JAK2 V617F

JAK2 exon 12

Polycythemia Vera

Myeloproliferative Neoplasm (MPN)

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Both DNA and RNA are extracted. The algorithm starts with a highly sensitive DNA-based JAK2 V617F test by allele specific polymerase chain reaction. If the JAK2 V617F result is negative or very low positive (0.06%-0.6%), JAK2 exon 12-15 Sanger sequencing will be performed on the stored RNA sample. If a JAK2 V617F mutation (>0.6%) is detected, no further testing will be performed.

 

The Sanger sequencing covers JAK2 exons 12 through the first 90% of exon 15, which spans the region containing essentially all mutations reported in myeloproliferative neoplasms. For more information, the following algorithms are available:

 

-Erythrocytosis Evaluation Testing Algorithm

-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation

-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation

Specimen Type
Describes the specimen type validated for testing

Varies

Shipping Instructions

Specimen must arrive within 5 days (120 hours) 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

Submit only 1 of the following specimens:

 

Specimen Type: Blood

Container/Tube: Lavender top (EDTA) or yellow top (ACD-B)

Specimen Volume: 10 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send whole blood specimen in original tube. Do not aliquot.

3. Label specimen as blood.

 

Specimen Type: Bone marrow aspirate

Container/Tube: Lavender top (EDTA) or yellow top (ACD-B)

Specimen Volume: 4 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send bone marrow specimen in original tube. Do not aliquot.

3. Label specimen as bone marrow.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

Blood: 8 mL

Bone Marrow: 2 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Paraffin-embedded bone marrow aspirate clot or biopsy blocks
Slides
Paraffin shavings
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
Varies Refrigerated (preferred) 5 days
Ambient 5 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in the distinction between the myeloproliferative neoplasm polycythemia vera and other secondary erythrocytosis

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Both DNA and RNA are extracted. The algorithm starts with a highly sensitive DNA-based JAK2 V617F test by allele specific polymerase chain reaction. If the JAK2 V617F result is negative or very low positive (0.06%-0.6%), JAK2 exon 12-15 Sanger sequencing will be performed on the stored RNA sample. If a JAK2 V617F mutation (>0.6%) is detected, no further testing will be performed.

 

The Sanger sequencing covers JAK2 exons 12 through the first 90% of exon 15, which spans the region containing essentially all mutations reported in myeloproliferative neoplasms. For more information, the following algorithms are available:

 

-Erythrocytosis Evaluation Testing Algorithm

-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation

-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

The Janus kinase 2 (JAK2) gene codes for a tyrosine kinase (JAK2) that is associated with the cytoplasmic portion of a variety of transmembrane cytokine and growth factor receptors important for signal transduction in hematopoietic cells. Signaling via JAK2 activation causes phosphorylation of downstream signal transducers and activators of transcription (STAT) proteins (eg, STAT5) ultimately leading to cell growth and differentiation. The JAK2 V617F mutation is located in exon 14 and present in 50% to 60% of primary myelofibrosis and essential thrombocythemia and in 95% to 98% of polycythemia vera (PV). In the rest of the PV cases, over 50 different mutations have been reported within exons 12 through 15 of JAK2, and essentially all of the non-V617F JAK2 mutations have been identified in PV. These mutations include point alterations and small insertions or deletions. Several of the exon 12 mutations have been shown to have biologic effects similar to those caused by the V617F mutation such that it is currently assumed other nonpolymorphic mutations have similar clinical effects. However, some mutations may not be well characterized and requires further clinical and research evaluation.

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 3 following states:

-Positive for JAK2 V617F mutation

-Positive for JAK2 mutation (other than V617F)

-Negative for JAK2 mutations

 

If the result is positive, a description of the mutation at the nucleotide level and the altered protein sequence are reported.

 

A positive mutation status is highly suggestive of a myeloid neoplasm and may support a diagnosis of polycythemia vera in the appropriate clinical setting. Correlation with clinicopathologic findings and other laboratory results is necessary in all cases.

 

A negative mutation status makes a diagnosis of polycythemia vera highly unlikely, although it does not completely exclude this possibility, other myeloproliferative neoplasms or other neoplasms.

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 diagnosis. Correlation with clinicopathologic findings and other laboratory results 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.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Baxter EJ, Scott LM, Campbell PJ, et al: Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet. 2005 Mar;365(9464):1054-1061. doi: 10.1016/S0140-6736(05)71142-9

2. James C, Ugo V, Le Couedic JP, et al: A unique clonal JAK2 mutation leading to constitutive signaling causes polycythaemia vera. Nature. 2005 Apr;434(7037):1144-1148. doi: 10.1038/nature03546

3. Kralovics R, Passamonti F, Buser AS, et al: A gain-of-function mutation of JAK2 in myeloproliferative disorders. N Engl J Med. 2005 Apr;352(17):1779-1790. doi: 10.1056/NEJMoa051113

4. Steensma DP, Dewald GW, Lasho TL, et al: The JAK2 V617F activating tyrosine kinase mutation is an infrequent event in both "atypical" myeloproliferative disorders and the myelodysplastic syndrome. Blood. 2005 Aug;106(4):1207-1209. doi: 10.1182/blood-2005-03-1183

5. Ma W, Kantarjian H, Zhang X, et al: Mutation profile of JAK2 transcripts in patients with chronic myeloid neoplasias. J Mol Diagn. 2009 Jan;11(1):49-53

6. Kilpivaara O, Levine RL: JAK2 and MPL mutations in myeloproliferative neoplasms: discovery and science. Leukemia. 2008 Oct;22(10):1813-1817. doi: 10.1038/leu.2008.229

7. Kravolics R: Genetic complexity of myeloproliferative neoplasms. Leukemia. 2008 Oct;22(10):1841-1848. doi: 10.1038/leu.2008.233

8. Defour JP, Chachoua I, Pecquet C, Constantinescu SN: Oncogenic activation of MPL/thrombopoietin receptor by 17 mutations at W515: implications for myeloproliferative neoplasms. Leukemia. 2016; 30:1214-1216. doi: 10.1038/leu.2015.271

9. Tefferi A: The classic myeloproliferative neoplasms: Chronic myelogenous leukemia, polycythemia vera, essential thrombocythemia, and primary myelofibrosis. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019, Accessed March 16, 2022. Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225078035&bookid=2709

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

Genomic DNA is extracted, and 2 polymerase chain reaction (PCR) reactions are used for each sample. In each reaction, a short fragment of genomic DNA, including the JAK2 V617 site, is amplified using quantitative PCR in a real-time PCR instrument. In the first reaction, the 5' terminal base of the reverse primer matches the JAK2 V617F mutated sequence and the PCR conditions are such that it will only bind the mutated DNA. In the second reaction, the 5' 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  and a negative cell line  and used to mitigate the run-to-run variation. Following each reaction, Relative Quantification Software is used to calculate the normalized mutated:wild-type ratio, which is expressed as a unitless ratio following correction with the calibrator data.

 

The formula for the normalized ratio is as follows:

 

Normalized ratio =

mutated/wild-type (sample)

mutated/wild-type (calibrator)

 

The final result is reported as % JAK2 V617F of total JAK2 (ie, [mutated/mutated + wild-type] x 100%).(Unpublished Mayo method)

 

For the Sanger sequencing, total RNA is extracted from whole blood or bone marrow and complementary DNA synthesized from JAK2 messenger RNA. A fragment spanning exons 12 through 15 is then amplified using standard PCR and the sequence is obtained using Sanger sequencing with analysis on an automated genetic analyzer.(Unpublished Mayo method)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

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.

7 to 10 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Blood/Bone marrow: 2 weeks; Extracted DNA and RNA: 3 months

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

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.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

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. This test 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.

81270-JAK2 V617

0027U (if appropriate)

LOINC® Information

Test Id Test Order Name Order LOINC Value
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.
PVJAK PV (JAK2 V617F, Exon 12-15) Reflex In Process
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.
MP037 Specimen Type 31208-2
42394 Final Diagnosis 50398-7
42395 PV Reflex Result 43399-5

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Create a PDF

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports