- CALR is a novel biomarker for detection of myeloproliferation neoplasm.
- Mutations in CALR are present in ~65-85% of essential thrombocythemia (ET) and primary myelofibrosis (PMF) patients that are JAK2- and MPL-mutation negative.
- out-of-frame insertion and/or deletions (indel) mutations in CALR exon 9 result in constitutive pathway activation and are early and disease initiating event
- CALR mutations are associated with decreased risk of thrombosis in ET and better survival in PMF compared to JAK2 mutations
- Rapid and sensitive detection of insertion and deletion-type mutations in exon 9 of CALR.
- Especially helpful to the pathologist in those bone marrow cases with ambiguous etiology of Thrombocytosis, equivocal bone marrow morphologic findings of MPN, and/or unexplained reticulin fibrosis.
- An aid in prognostication of PMF and thrombosis risk assessment in ET.
When to go for the test:
Patients who are suspected of having an MPN and who have tested negative for BCR-ABL1 and JAK2 mutations are suitable for testing.