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HelpTest Code PVJAK Polycythemia Vera, JAK2 V617F with Reflex to JAK2 Exon 12-15, Sequencing for Erythrocytosis, Varies
Reporting Name
PV (JAK2 V617F, Exon 12-15) ReflexPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
Aiding in the distinction between the myeloproliferative neoplasm polycythemia vera and other secondary erythrocytosis
Method Name
Allele-Specific Polymerase Chain Reaction (PCR) and Sanger Sequencing
Shipping Instructions
Specimen must arrive within 5 days of collection.
Necessary Information
Specimen Required
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.
Specimen Type
VariesSpecimen Minimum Volume
Blood: 8 mL; Bone marrow: 2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Refrigerated (preferred) | 5 days | |
| Ambient | 5 days |
Reject Due To
| Gross hemolysis | Reject |
| Paraffin-embedded bone marrow aspirate clot or biopsy blocks Slides Paraffin shavings Moderately to severely clotted |
Reject |
Reference Values
An interpretive report will be provided.
Interpretation
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.
Day(s) Performed
Monday through Saturday
Report Available
7 to 10 daysTest 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.CPT Code Information
81270-JAK2 V617
0027U (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PVJAK | PV (JAK2 V617F, Exon 12-15) Reflex | In Process |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 42395 | PV Reflex Result | 43399-5 |
| MP037 | Specimen Type | 31208-2 |
| 42394 | Final Diagnosis | 50398-7 |
Forms
If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.
Reflex 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
The test 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%-2%), JAK2 exon 12-15 Sanger sequencing will be performed on the stored RNA sample. If a JAK2 V617F mutation (>2%) 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 see:
-Erythrocytosis Evaluation Testing Algorithm
-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation
-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation