Dehydrated Hereditary Stomatocytosis 1 with or Without Pseudohyperkalemia and/or Perinatal Edema, also known as dehydrated hereditary stomatocytosis, is related to hereditary stomatocytosis and pseudohyperkalemia, familial, 2, due to red cell leak. An important gene associated with Dehydrated Hereditary Stomatocytosis 1 with or Without Pseudohyperkalemia and/or Perinatal Edema is PIEZO1 (Piezo Type Mechanosensitive Ion Channel Component 1 (Er Blood Group)), and among its related pathways/superpathways are Transport of inorganic cations/anions and amino acids/oligopeptides and MAPK-Erk Pathway. Affiliated tissues include spleen and monocytes, and related phenotypes are hemolytic anemia and increased red cell osmotic fragility