Erythrocytosis, Familial, 7, also known as familial erythrocytosis 7, is related to hemoglobin m disease and glutathione peroxidase deficiency. An important gene associated with Erythrocytosis, Familial, 7 is HBA2 (Hemoglobin Subunit Alpha 2), and among its related pathways/superpathways are Transport of inorganic cations/anions and amino acids/oligopeptides and Oxidation by cytochrome P450. Related phenotypes are polycythemia and increased hematocrit