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HelpMayo Test ID JAK2P JAK2 (9p24.1) Rearrangement, Hematologic Disorders, FISH, Tissue
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
Provide a reason for testing and pathology report with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Tissue
Preferred: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded (FFPE) tumor tissue block. Blocks prepared with alternative fixation methods may be acceptable; provide fixation method used.
Acceptable: Slides
Collection Instructions: Four consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.
Useful For
Providing diagnostic information for hematologic malignancies
Aiding in the determination of whether a targeted JAK2 inhibitor could be useful for therapy
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| _PBCT | Probe, +2 | No | No |
| _PADD | Probe, +1 | No | No |
| _PB02 | Probe, +2 | No | No |
| _PB03 | Probe, +3 | No | No |
| _IL25 | Interphases, <25 | No | No |
| _I099 | Interphases, 25-99 | No | No |
| _I300 | Interphases, >=100 | No | No |
Testing Algorithm
This test does not include a pathology consult. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered, and the appropriate fluorescence in situ hybridization (FISH) test will be performed at an additional charge.
This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results. Additional charges will be incurred for all reflex probes performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.
Appropriate ancillary probes may be performed at consultant discretion to render comprehensive assessment. Any additional probes will have the results included within the final report and will be performed at an additional charge.
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
JAK2 (9p24.1) Rearrangement,FISH,TsSpecimen Type
TissueSpecimen Minimum Volume
Two consecutive, unstained, 5- micron- thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Tissue | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
No specimen should be rejected.Clinical Information
The JAK2 gene codes for a protein tyrosine kinase involved in cytokine signaling. Chromosomal translocations involving JAK2 can lead to the formation of chimeric oncoproteins in hematologic malignancies. Rearrangements involving 9p24.1 are rare abnormalities seen in various hematologic diseases and are typically aggressive. Identification of opportunities to apply targeted therapy with JAK2 inhibitors can be helpful for patients with JAK2 rearrangements.
Reference Values
An interpretive report will be provided.
Interpretation
A positive result is detected when the percent of cells with an abnormality exceeds the normal cutoff for the probe set.
A positive result suggests rearrangement of the JAK2 locus. A negative result suggests no rearrangement of the JAK2 gene region at 9p24.1.
Cautions
This test is not approved by the US Food and Drug Administration, and it is best used as an adjunct to existing clinical and pathologic information.
Fixatives other than formalin (eg, Prefer, Bouin) may not be successful for fluorescence in situ hybridization (FISH) assays, however nonformalin-fixed samples will not be rejected.
Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.
Clinical Reference
1. Chase A, Bryant C, Score J, et al: Ruxolitinib as potential targeted therapy for patients with JAK2 rearrangements. Haematologica. 2013;98(3):404-408
2. Van Roosbroeck K, Cox L, Tousseyn T, et al: JAK2 rearrangements, including the novel SEC31A-JAK2 fusion, are recurrent in classical Hodgkin lymphoma. Blood. 2011;117(15):4056-4064
3. Roberts K, Li Y, Payne-Turner D, et al: Targetable kinase-activating lesions in Ph-like acute lymphoblastic leukemia. N Engl J Med. 2014;371:1005-101
4. Springuel L, Renauld JC, Knoops L: JAK kinase targeting in hematologic malignancies: a sinuous pathway from identification of genetic alteration towards clinical indications. Haematologica. 2015;100:1240-1253
5. Reshmi SC, Harvey RC, Roberts KG, et al: Targetable kinase gene fusions in high-risk B-ALL: A study from the Children's Oncology Group. Blood. 2017;129:3352-3361
Method Description
The test is performed using a laboratory-developed JAK2 (9p24.1) dual-color break-apart strategy probe (BAP). The probe set is hybridized to the appropriate target areas and 2 technologists each analyze 50 interphase nuclei (100 total) with the results expressed as the percent of abnormal nuclei.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysSpecimen Retention Time
Slides and H and E: Indefinitely. Client provided paraffin blocks and extra unstained slides (if provided) will be returned after testing is complete.Performing Laboratory
Mayo Clinic Laboratories in Rochester
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.CPT Code Information
88271 x 2, 88291-DNA probe, each (first probe set), Interpretation and report
88271 x 2-DNA probe, each; each additional probe set (if appropriate)
88271 x 1-DNA probe, each; coverage for sets containing 3 probes (if appropriate)
88271 x 2-DNA probe, each; coverage for sets containing 4 probes (if appropriate)
88271 x 3-DNA probe, each; coverage for sets containing 5 probes (if appropriate)
88274-w/modifier 52-Interphase in situ hybridization, <25 cells, each probe set (if appropriate)
88274-Interphase in situ hybridization, 25 to 99 cells, each probe set (if appropriate)
88275-Interphase in situ hybridization, 100 to 300 cells, each probe set (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| JAK2P | JAK2 (9p24.1) Rearrangement,FISH,Ts | In Process |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 606822 | Result Summary | 62357-9 |
| 606823 | Interpretation | 69965-2 |
| 606824 | Result | 62356-1 |
| GC052 | Reason for Referral | 42349-1 |
| 606825 | Specimen | 31208-2 |
| 606826 | Source | 31208-2 |
| 606827 | Tissue ID | 80398-1 |
| 606828 | Method | 85069-3 |
| 606829 | Additional Information | 48767-8 |
| 606830 | Disclaimer | 62364-5 |
| 606831 | Released By | 18771-6 |