JAK2, CALR, and MPL Mutations in Egyptian Patients With Classic Philadelphia-negative Myeloproliferative Neoplasms

Clin Lymphoma Myeloma Leuk. 2020 Oct;20(10):e645-e651. doi: 10.1016/j.clml.2020.05.011. Epub 2020 May 16.

Abstract

Background: Genetic mutations have been proven to be one of the major criteria in the diagnosis and distinction of different myeloproliferative neoplasm (MPN) subtypes. Therefore, the aim of this study was to determine the molecular profile of Egyptian patients with MPN subtypes and correlate with clinicopathological status.

Methods: A series of 200 patients with MPNs (92 polycythemia vera, 68 essential thrombocythemia, and 40 primary myelofibrosis) were included in this study. DNA from each sample was amplified using polymerase chain reaction to detect Janus kinase 2 (JAK2), calreticulin (CALR), and myeloproliferative leukemia virus oncogene (MPL) mutations. Sanger sequencing was used to determine the mutation types.

Results: Of the 200 samples, 44% had JAK2V617F and 10% were carrying CALR mutation with type 2 being the most frequent type in this study (55%). No MPL or JAK2 exon 12 mutations were detected. All clinical and hematological data had no differences with other populations except that our CALR-positive patients showed a decrease in the platelet count compared with JAK2V617F-positive patients.

Conclusion: Our study on Egyptian patients shows a specific molecular profile of JAK2 mutation, and CALR mutation type 2 was higher than type 1.

Keywords: CALR; Essential thrombocytosis; JAK2; Polycythemia vera; Primary myelofibrosis.

MeSH terms

  • Adult
  • Calreticulin / metabolism*
  • Egypt
  • Female
  • Humans
  • Janus Kinase 2 / metabolism*
  • Male
  • Middle Aged
  • Mutation
  • Myeloproliferative Disorders / genetics*

Substances

  • Calreticulin
  • JAK2 protein, human
  • Janus Kinase 2