Polycythaemia-inducing mutations in the erythropoietin receptor (EPOR): mechanism and function as elucidated by epidermal growth factor receptor-EPOR chimeras.
Erythropoietin hypersensitivity in primary familial and congenital polycythemia: role of tyrosines Y285 and Y344 in erythropoietin receptor cytoplasmic domain.
JAK2(V617F) failed to induce polycythemia in recipients after deletion of Stat5a/b, although the loss of STAT5 did not prevent the development of myelofibrosis.
Irp1(-/-) mice develop polycythemia and pulmonary hypertension, and when these mice are challenged with a low iron diet, they die early of abdominal hemorrhages, suggesting that Irp1 plays an essential role in erythropoiesis and in the pulmonary and cardiovascular systems.
Hemopoietic Cell Kinase amplification with Protein Tyrosine Phosphatase Receptor T depletion leads to polycythemia, aberrant marrow erythoid maturation, and splenomegaly.
A new abnormal hemoglobin, Hb Villejuif [beta 123(H1) Thr----Ile] has been discovered during the exploration of a polycythemia in a 87-year-old patient of French origin.
All of these rearrangements result in truncation of the cytoplasmic tail of EPOR at residues similar to those mutated in primary familial congenital polycythemia, with preservation of the proximal tyrosine essential for receptor activation and loss of distal regulatory residues.
At the forefront are the mutually exclusive exon 14 (JAK2V617F) and exon 12 JAK2 mutations that are almost always present in PV but not in polycythemias of other causes.
Beyond this, when C-terminal truncated hEPOR-T mutant alleles as harbored by polycythemia patients are co-expressed with the wild-type EPOR in EPO-dependent erythroid progenitors, several specific events become altered.
Beyond this, when C-terminal truncated hEPOR-T mutant alleles as harbored by polycythemia patients are co-expressed with the wild-type EPOR in EPO-dependent erythroid progenitors, several specific events become altered.
Chuvash polycythemia is a rare congenital form of polycythemia caused by homozygous R200W and H191D mutations in the VHL (von Hippel-Lindau) gene, whose gene product is the principal negative regulator of hypoxia-inducible factor.
Consequently, hypoxia-treated <i>Jnk2</i><sup>-/-</sup> mice had reduced erythropoiesis and were less prone to polycythemia because of decreased expression of the HIF target gene erythropoietin (<i>Epo</i>).
Conversely, the patient with life-long erythrocytosis is more likely to suffer from congenital polycythemia and should therefore be evaluated for germline mutations that result in enhanced Epo effect (for example, Epo receptor mutations), altered intracellular oxygen sensing (for example, mutations involving the von Hippel-Lindau tumor suppressor gene) or decreased P50 (for example, high-oxygen-affinity hemoglobinopathy).