title: Calreticulin mutation burden--is it a stable clone in patients with essential thrombocythemia and myelofibrosis?
abstract: Calreticulin mutation represents the second most frequent mutation after JAK2 V617F in myeloproliferative disorder and is considered to be a driving mutation. Herein the mutation burden was evaluated in patients with essential thrombocythemia or myelofibrosis and found to increase by 5.7% over time unrelated to the time elapsed from the initial to the final positive test. The longer the course of the disease when first tested (range 0-30 years, mean 7.9 years) the lower mutation burden was observed. The mutated clone was larger in type II in comparison with type I mutation when first tested but the difference in mutation burden from the final to the first positive test was significantly higher in those with type I. Similarly, the difference in mutation burden was higher in patients with essential thrombocythemia reaching almost 8% in comparison to 1.3% in post-essential thrombocythemia myelofibrosis. Thus a repeat calreticulin quantitative test is not warranted.
authors.affiliation: Hematology Laboratory, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Shuly
authors.affiliation: Hematology Laboratory, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Meital
authors.initials: M
authors.lastname: Nagar
authors.affiliation: Hematology Laboratory, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Lior
authors.initials: L
authors.lastname: Ben-Asaf
authors.affiliation: Hematology Department, Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Abraham
authors.initials: A
authors.lastname: Kneller
authors.affiliation: Department of Statistics and Operations Research, Faculty of Exact Sciences, Tel Aviv University, Israel.
authors.forename: David M
authors.initials: DM
authors.lastname: Steinberg
authors.affiliation: Hematology Laboratory, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Ninette
authors.initials: N
authors.lastname: Amariglio
authors.affiliation: Thrombosis and Hemostasis Unit, Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine, Tel Aviv University, Israel. Electronic address: ophiras@sheba.health.gov.il.
authors.forename: Ophira
authors.initials: O
authors.lastname: Salomon
mesh_terms: D037282:Calreticulin / Q000235:genetics*; D060965:Clonal Evolution / Q000235:genetics; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics; D008297:Male; D009154:Mutation; D010641:Phenotype; D055728:Primary Myelofibrosis / Q000235:genetics*; D013920:Thrombocythemia, Essential / Q000235:genetics*
chemical_list: D037282:Calreticulin; D016044:Fusion Proteins, bcr-abl; D053614:Janus Kinase 2
keywords: Calreticulin; Essential thrombocythemia; Myelofibrosis