Test Code JAK2M JAK2 V617F Mutation Detection, Bone Marrow
Reporting Name
JAK2 V617F Mutation Detection, BMUseful For
Aiding in the distinction between a reactive blood cytosis and a chronic myeloproliferative disorder using bone marrow specimens
Testing Algorithm
For information see Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation.
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
Bone MarrowShipping Instructions
Specimen must arrive within 7 days of collection.
Specimen Required
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 2 mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Send bone marrow specimen in original tube. Do not aliquot.
Specimen Minimum Volume
1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Bone Marrow | Ambient (preferred) | 7 days | PURPLE OR PINK TOP/EDTA |
Refrigerated | 7 days | PURPLE OR PINK TOP/EDTA |
Special Instructions
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Friday
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 |
---|---|---|
JAK2M | JAK2 V617F Mutation Detection, BM | 72333-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
39723 | JAK2 Result | 53761-3 |
31157 | JAK2 V617F Mutation Detection, BM | 72333-8 |
Method Description
Genomic DNA is extracted, and 2 polymerase chain reactions (PCR) 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 wildtype 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 wildtype 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:wildtype 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/wildtype (sample) |
mutated/wildtype (calibrator) |
The final result is reported as percent JAK2 V617F of total JAK2 (ie, [mutated/mutated + wildtype] x 100%), calculated from the normalized mutated:wildtype ratio.(Unpublished Mayo method)
Report Available
2 to 5 daysReject Due To
Gross hemolysis | Reject |
Moderately to severely clotted | Reject |
Test Classification
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.Method Name
Quantitative Polymerase Chain Reaction (PCR)
Forms
1. Hematopathology Patient Information (T676)
2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.