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HelpTest Code CALR CALR Mutation Analysis, Myeloproliferative Neoplasm (MPN), Varies
Reporting Name
MPN, CALR Gene Mutation, Exon 9Useful For
Rapid and sensitive detection of insertion and deletion-type mutations in exon 9 of CALR
An aid in distinction between reactive thrombocytosis and leukocytosis versus a myeloproliferative neoplasm (MPN), especially essential thrombocythemia (ET) and primary myelofibrosis (PMF), and is highly informative in cases in which JAK2 and MPL testing are negative
Especially helpful to the pathologist in those bone marrow cases with ambiguous etiology of thrombocytosis, equivocal bone marrow morphologic findings of MPN, and unexplained reticulin fibrosis
An aid in prognostication of PMF and thrombosis risk assessment in ET
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
VariesShipping Instructions
Specimen must arrive within 7 days (168 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
Submit only 1 of the following specimens:
Specimen Type: Peripheral blood
Container/Tube: EDTA (lavender top) or ACD-B (yellow top)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send specimen in original tube.
3. Label specimen as blood.
Specimen Stability: Ambient (preferred)/Refrigerate
Specimen Type: Bone marrow
Container/Tube: EDTA (lavender top) or ACD-B (yellow top)
Specimen Volume: 2 mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Send specimen in original tube.
3. Label specimen as bone marrow.
Specimen Stability: Ambient (preferred)/Refrigerate
Specimen Type: Extracted DNA from blood or bone marrow
Container/Tube: 1.5- to 2-mL tube
Specimen Volume: Entire specimen
Collection Instructions: Label specimen as extracted DNA from blood or bone marrow and include indication of volume and concentration of the DNA.
Specimen Stability: Frozen (preferred)/Refrigerate/Ambient
Specimen Minimum Volume
1 mL
Testing Algorithm
The following algorithms are available in Special Instructions:
-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation
-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | 7 days |
Special Instructions
Reference Values
An interpretive report will be provided
Day(s) and Time(s) Performed
Monday through Friday; 8 a.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
81219-CALR (calreticulin) (eg, myeloproliferative disorders), gene analysis, common variants in exon 9
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CALR | MPN, CALR Gene Mutation, Exon 9 | 77174-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| MP020 | Specimen | 31208-2 |
| 36301 | Final Diagnosis | 22637-3 |
Clinical Reference
1. Klampfl T, Gisslinger H, Harutyunyan AS, et al: Somatic mutation of calreticulin in myeloproliferative neoplasms. N Engl J Med 2013;369:2379-90
2. Nangalia J, Massie CE, Baxter EJ, et al: Somatic CALR mutation in myeloproliferative neoplasms with nonmutated JAK2. N Engl J Med 2013;369:2391-2405
3. Rumi E, Pietra D, Ferretti V, et al: JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 2014 Mar 6;123(10):1544-1551
4. Rotunno G, Mannarelli C, Guglielmelli P, et al: Impact of calreticulin mutations on clinical and hematological phenotype and outcome in essential thrombocythemia. Blood 2014;123(10):1552-1555
5. Tefferi A, Lasho TL, Finke CM, et al: CALR vs JAK2 vs MPL-mutated or triple-negative myelofibrosis: clinical, cytogenetic and molecular comparisons. Leukemia 2014 Jul;28(7):1472-1477
Method Description
PCR amplification of CALR exon 9 is performed on DNA isolated from the patient sample. The PCR product is then run on an ABI 3130xl Genetic Analyzer for fragment analysis to detect insertions and deletions. An unmutated CALR will show an amplicon at 266 bp, a mutated CALR with insertion will show an amplicon greater than 266 bp, and a mutated CALR with deletion will show an amplicon smaller than 266 bp. This assay has an analytical sensitivity of approximately 6% (ie, 6 mutation-containing cells in 100 total cells) in most mutation types, except for the rare type of 1-bp deletion, which has a sensitivity of approximately 20%. This is a laboratory developed test using analyte-specific reagents and research use only (RUO) reagents.(Unpublished Mayo method)
Analytic Time
3 daysReject Due To
| Gross hemolysis | Reject |
| Other | Paraffin-embedded bone marrow aspirate clot Bone marrow biopsies, slides, or paraffin shavings Moderately to severely clotted |
Method Name
Polymerase Chain Reaction (PCR) and Fragment Analysis
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.