Molecular and clinical features of the myeloproliferative neoplasm associated with JAK2 exon 12 mutations.

Abstract

Although approximately 95% of patients with polycythemia vera (PV) harbor the V617F mutation in JAK2 exon 14, several mutations in exon 12 have been described in the remaining patients. We conducted a European collaborative study to define the molecular and clinical features of patients harboring these mutations. Overall, 106 PVs were recruited and 17 different mutations identified. Irrespective of the mutation, two-thirds of patients had isolated erythrocytosis, whereas the remaining subjects had erythrocytosis plus leukocytosis and/or thrombocytosis. Compared with JAK2 (V617F)-positive PV patients, those with exon 12 mutations had significantly higher hemoglobin level and lower platelet and leukocyte counts at diagnosis but similar incidences of thrombosis, myelofibrosis, leukemia, and death. In a multivariable analysis, age more than 60 years and prior thrombosis predicted thrombosis. These findings suggest that, despite the phenotypical difference, the outcome of JAK2 exon 12 mutations-positive PV is similar to that of JAK2 (V617F)-positive PV.

• Authors: Francesco Passamonti, Chiara Elena, Susanne Schnittger, Radek C Skoda, Anthony R Green, François Girodon, Jean-Jacques Kiladjian, Mary Frances McMullin, Marco Ruggeri, Carles Besses, Alessandro M Vannucchi, Eric Lippert, Heinz Gisslinger, Elisa Rumi, Thomas Lehmann, Christina A Ortmann, Daniela Pietra, Cristiana Pascutto, Torsten Haferlach, Mario Cazzola
• Journal: Blood (Blood) Vol. 117 Issue 10 Pg. 2813-6 (Mar 10 2011) ISSN: 1528-0020 [Electronic] United States
• PMID: 21224469 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• JAK2 protein, human
• Janus Kinase 2

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Exons
• Female
• Humans
• In Situ Hybridization
• Janus Kinase 2 (genetics)
• Leukocytosis (etiology, genetics)
• Male
• Middle Aged
• Mutation
• Polycythemia (etiology, genetics)
• Polycythemia Vera (complications, genetics, mortality)
• Polymerase Chain Reaction
• Thrombocytosis (etiology, genetics)
• Young Adult