In secondary erythrocytosis, the elevated red cell count is powered by factors outside the erythroid compartment, for instance by raised erythropoietin (EPO) synthesis based on congenital defects of the oxygen-sensing pathway. The principal transcriptional regulator of EPO synthesis is endothelial PAS domain-containing protein 1 (EPAS 1). We present here the first report of a patient with erythrocytosis involving a mutation of amino acid 525 in EPAS1. The p.Asp525His mutation affects a residue that is farthermost from primary functional site Pro-531 of any of the erythrocytosis-related mutations that have been identified up to now.
Keywords: Asp525His; EPAS1; erythrocytosis; erythropoietin synthesis; oxygen-sensing pathway.
© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.