JAK2 V617F mutation, mesenteric vein thrombosis, and myeloproliferative disorders.

Mesenteric vein thrombosis is a rare disorder that is often the first manifestation of a systemic condition such as a hypercoagulable state or cancer. In particular, myeloproliferative disorders can present as mesenteric vein thrombosis even in the setting of relatively normal peripheral blood counts. A recent novel mutation in the Janus activated kinase 2 gene involving a gain-of-function substitute of valine to phenylalanine at position 617 (JAK2 V617F) has been discovered to be prevalent in patients with mesenteric vein thrombosis and myeloproliferative disorders. This article reports a patient who presented with mesenteric vein thrombosis and relatively normal peripheral blood counts. He was diagnosed with essential thrombocythemia after he tested positive for the JAK2 V617F mutation.