RT Book, Section A1 Bissonnette, Bruno A1 Luginbuehl, Igor A1 Engelhardt, Thomas SR Print(0) ID 1164072876 T1 Hereditary Xerocytosis T2 Syndromes: Rapid Recognition and Perioperative Implications, 2e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9781259861789 LK accesspediatrics.mhmedical.com/content.aspx?aid=1164072876 RD 2024/10/07 AB Hereditary xerocytosis is characterized by red cell membrane abnormality with increased permeability to cations and a greater efflux of potassium than of sodium. It is a rare, autosomal dominant congenital hemolytic anemia characterized by macrocytic stomatocytosis, and decreased red cell osmotic fragility due to a defect in cation permeability. Consequently, these red cells lose potassium in excess of sodium gained, with a decrease in total cation content. Osmotically resistant xerocytes result. Clinically, the patient may present with episodes of fatigue, jaundice, pallor, and darkened urine, especially during intense physical activity. At the other end of the spectrum from xerocytosis is hereditary stomatocytosis (or hydrocytosis), in which the red cells are overhydrated and sodium loaded.