The exon 14 JAK2 V617F mutation has been well established as a driver mutation in polycythemia vera (PV) and other myeloproliferative neoplasms. JAK2 exon 12 mutations have also been implicated in PV, although patients with these mutations may show isolated erythrocytosis. Recently additional JAK2point mutations have been described-all in regions encoding the pseudokinase domain that regulates ...

E RYTHROCYTOSIS has been associated with various types of tumors.1 In some of these cases, the tumor was found to contain a substance which was similar to erythropoietin both immunochemically and in biologic activity. We shall here describe what we believe to be the first reported case of a patient with a leiomyoma of the esophagus and erythrocytosis. Experiments to determine the etiology of th...

Erythroid progenitor growth, the serum hormones that regulate erythropoiesis, and the effect of patient's serum on the growth of normal erythroid progenitors were assessed in eight patients with end-stage renal disease (ESRD) and erythrocytosis. All patients were male and had been on maintenance dialysis, they had a hematocrit >50% and/or a red blood cell count >6 x 10(12)/L and an arterial oxy...