Test Name
Calreticulin Exon 9 Mutation Analysis
Test Code
M CALR
Synonyms
Calreticulin Exon 9; Chromosome 19p13.3-13.2
Associations
Essential thrombocythemia (ET) – 67% of JAK2 and MPL negative cases
Primary myelofibrosis (PMF) –88% of JAK2 and MPL negative cases
Reflex Testing
May be of interest to further evaluate involvement by Primary Myelofibrosis or Essential Thrombocythemia if JAK2 V617F is negative
CPT Codes
81219
Turnaround Time
10 days
Specimen Requirements
5.0 mL (min. 1.0 mL) whole blood EDTA preferred, heparin whole blood accepted 3.0 mL (min. 1.0 mL) bone marrow aspirate EDTA preferred, heparin accepted
Specimen Stability
EDTA whole blood or bone marrow stable at room temperature (18-25°C)
Storage & Handling
Whole blood and bone marrow ship in a Styrofoam container with a cool pack. (Do not allow cool/refrigerated pack to directly contact sample
Causes for Rejections
Insufficient DNA content; Insufficient specimen volume; Specimen at incorrect temperature; Incorrect anticoagulant
Description
CALR somatic mutations are seen in a subset of patients with MPNs who lack JAK2 and MPL mutations. CALR mutations appear restricted to patients with ET and PMF and are not found in patients with polycythemia vera. CALR mutated ET and PMF are associated w
References
- Arber et al. (2106). The 2016 revision to the World Health Organization Classification of Myeloid Neoplasms and Acute Leukemia. Blood. 2016 May 19;127(20):2391-405
- Vainchenker W, Kralovics R. (2017) Genetic basis and molecular pathophysiology of classical myeloproliferative neoplasms. Blood. 2017 Feb 9;129(6):667-679
- Klampfl T. et al. 2013. Somatic mutations of calreticulin in myeloproliferative neoplasms. N Engl J Med.Dec 9;369(25):2379-90
- Nangalia J. et al. 2013. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2.N Engl J Med,Dec 19;369(25):2391-405
