Dysregulation of the HIF pathway due to VHL mutation causing severe erythrocytosis and pulmonary arterial hypertension

To the editor: Hereditary erythrocytosis can be caused by mutations in genes involved in the hypoxia-inducible factor (HIF) pathway.[1][1]–[3][2] For example, Chuvash polycythemia is caused by an R200W substitution in the von Hippel–Lindau protein (VHL).[1][1] There is increasing evidence