Algorithm for the Diagnosis of Erythrocytosis

Algorithm for the Diagnosis of Erythrocytosis

* Some patients with obstructive sleep apnea will have normal oxygen saturation when seen in the office.

† A homozygous mutation in the EGLN1 gene leads to Chuvash polycythemia.

‡ EGLN1 is a protein encoded by the EPAS1 gene.

§ EPAS1 (also known as hypoxia-inducible factor-2alpha [HIF-2alpha]) is a protein encoded by the gene.

EGLN1 = egl-9 family hypoxia inducible factor 1; EPAS1 = endothelial PAS domain-containing protein 1; VHL = von Hippel-Lindau.

Data from Spivak JL, Silver RT. The revised World Health Organization diagnostic criteria for polycythemia vera, essential thrombocytosis, and primary myelofibrosis: an alternative proposal. Blood. 2008;112(2):231-239. doi:10.1182/blood-2007-12-128454