Hereditary Cryohydrocytosis

Hereditary cryohydrocytosis (CH) is an unusual haemolytic anaemia considered a variant of hereditary stomatocytosis in which the red cell membrane is abnormally permeable to Na+ and K+ at both body and (even more prominently) refrigerator temperatures. Therefore,  if whole blood is anticoagulated in heparin or EDTA and stored on ice overnight, about 50% of the cells lyse. Patients with cryohydrocytosis show an excess of ether lipids in the membrane but they differ from familial pseudohyperkalaemia in that the leak showed different temperature profiles.