Test Code CALR CALR Mutation Analysis, Myeloproliferative Neoplasm (MPN), Varies
Useful For
Rapid and sensitive detection of insertion and deletion-type mutations in exon 9 of CALR
Aiding in distinguishing 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
Aiding in the prognostication of PMF and thrombosis risk assessment in ET
Special Instructions
Reporting Name
MPN, CALR Gene Mutation, Exon 9Specimen Type
VariesOrdering Guidance
Shipping Instructions
Specimen must arrive within 7 days of collection.
Necessary Information
Specimen source is required
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA) or yellow top (ACD)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Label specimen as blood.
3. Send whole blood specimen in original tube. Do not aliquot.
Specimen Stability Information: Ambient (preferred)/Refrigerate
Additional Information: To ensure minimum volume and concentration of DNA is met, the preferred volume of blood must be submitted. Testing may be canceled if DNA requirements are inadequate.
Specimen Type: Bone marrow
Container/Tube: Lavender top (EDTA) or yellow top (ACD
Specimen Volume: 2 mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Label specimen as bone marrow.
3. Send bone marrow specimen in original tube. Do not aliquot.
Specimen Stability Information: 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:
1. Label specimen as extracted DNA from blood or bone marrow
2. Include indication of volume and concentration of the DNA.
Specimen Stability Information: Frozen (preferred)/Refrigerate/Ambient
Specimen Minimum Volume
Whole blood/bone marrow: 1 mL; Extracted DNA: 50 mcl at 20 ng/mcL concentration
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Varies | 7 days |
Reference Values
An interpretive report will be provided
Interpretation
An interpretive report will be issued.
The results will be reported as 1 of the 3 states if DNA amplification is successful (see Cautions):
-Positive. A deletion-insertion-type mutation was detected in CALR, exon 9.
-Negative. No deletion or insertion was detected in CALR, exon 9.
-Equivocal. A small amplicon suspicious for a deletion-insertion type mutation was detected in CALR, exon 9.
Positive mutation status is highly suggestive of a myeloid neoplasm but must be correlated with clinical and other laboratory and morphologic features for definitive diagnosis.
Negative mutation status does not exclude the presence of a myeloproliferative neoplasm or other neoplastic disorders.
Clinical Reference
1. Klampfl T, Gisslinger H, Harutyunyan AS, et al. Somatic mutation of calreticulin in myeloproliferative neoplasms. N Engl J Med. 2013;369(25):2379-2390
2. Nangalia J, Massie CE, Baxter EJ, et al. Somatic CALR mutation in myeloproliferative neoplasms with nonmutated JAK2. N Engl J Med. 2013;369(25):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;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;28(7):1472-1477
6. Greenfield G, McMullin MF, Mils K. Molecular pathogenesis of the myeloproliferative neoplasms. J Hematol Oncol. 2021;14(1):103
Day(s) Performed
Monday through Friday
Report Available
3 to 5 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest 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
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 |
Testing Algorithm
The following algorithms are available:
-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation
-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation
Method Name
Polymerase Chain Reaction (PCR) and Fragment Analysis
Forms
1. Hematopathology Patient Information (T676)
2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.