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Test Code JK617 JAK2 V617F Mutation Detection, Blood

Reporting Name

JAK2 V617F Mutation Detection, B

Useful For

Aiding in the distinction between a reactive blood cytosis and a chronic myeloproliferative disorder in peripheral blood specimens

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Whole Blood EDTA


Shipping Instructions


Specimen must arrive within 7 days of draw.



Specimen Required


Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: Yellow top (ACD)

Specimen Volume: 4 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.


Specimen Minimum Volume

1 mL

Testing Algorithm

The following algorithms are available in Special Instructions:

-Erythrocytosis Evaluation Testing Algorithm

-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Ambient (preferred) 7 days PURPLE OR PINK TOP/EDTA
  Refrigerated  7 days PURPLE OR PINK TOP/EDTA

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday; 12 p.m.

Test Classification

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 U.S. Food and Drug Administration.

CPT Code Information

81270-JAK2 (Janus kinase 2) (eg, myeloproliferative disorder) gene analysis, p.Val617Phe (V617F) variant

LOINC Code Information

Test ID Test Order Name Order LOINC Value
JAK2B JAK2 V617F Mutation Detection, B 43399-5

 

Result ID Test Result Name Result LOINC Value
39722 JAK2 Result 53761-3
29590 JAK2 V617F Mutation Detection, B 43399-5

Clinical Reference

1. Baxter EJ, Scott LM, Campbell PJ, et al: Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005 March 16;365(9464):1054-1061

2. James C, Ugo V, Le Couedic JP, et al: A unique clonal JAK2 mutation leading to constitutive signaling causes polycythaemia vera. Nature 2005 April 28;434(7037):1144-1148

3. Kralovics R, Passamonti F, Buser AS, et al: A gain-of-function mutation of JAK2 in myeloproliferative disorders. N Engl J Med 2005;352:1779-1790

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;106:1207-1209

5. Gong, Jerald Z, Cook, James R, et al: Laboratory Practice Guidelines for Detecting and Reporting JAK2 and MPL Mutations in Myeloproliferative Neoplasms. J Mol Diag 2013;15(6):733-744

Method Description

Genomic DNA is extracted and 2 PCR reactions are used for each sample. 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 5' 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 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 (HEL) and a negative cell line (HL60) that 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 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 percent JAK2 V617F of total JAK2 (ie, [mutated/mutated + wild-type] x 100%) calculated from the normalized mutated:wild-type ratio.(Unpublished Mayo method)

Analytic Time

2 days

Reject Due To

Gross hemolysis Reject
Other Moderately to severely clotted

Method Name

Point Mutation Detection in DNA using Quantitative Polymerase Chain Reaction (PCR)

Forms

1. Hematopathology Patient Information (T676) in Special Instructions

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

Secondary ID

88715