Stomatocytosis is absent in "stomatin"-deficient murine red blood cells

To examine the relationship between erythrocyte membrane protein 7.2b defic iency and the hemolytic anemia of human hereditary stomatocytosis, we creat ed 7.2b knock-out mice by standard gene targeting approaches. Immunoblots s howed that homozygous knock-out mice completely lacked erythrocyte protein 7.2b. Despite the absence of protein 7.2b, there was no hemolytic anemia an d mouse red blood cells (RBCs) were normal in morphology, cell indices, hyd ration status, monovalent cation content, and ability to translocate lipids . The absence of the phenotype of hereditary stomatocytosis implies that pr otein 7.2b deficiency plays no direct role in the etiology of this disorder and casts doubt on the previously proposed role of this protein as a media tor of cation transport in RBC. (C) 1999 by The American Society of Hematol ogy.