ELLIPTOCYTOSIS

Hematologic disorder characterized by elliptically shaped red blood cells (elliptocytosis) with variable breakup of red cells (hemolysis) and varying degrees of anemia. Inherited as a dominant trait. Due to mutation (change) in one of the genes encoding proteins of the red cell membrane skeleton. In 1956 Newton Morton brilliantly showed that there were at least 2 forms of elliptocytosis, one form unlinked to the Rh blood group and another form linked to Rh (now known to be on chromosome 1). The Rh-linked form, (EL1) in chromosome region 1p34.2-p33 is due to a mutation in erythrocyte membrane protein 4.1. Forms of elliptocytosis not linked to Rh are due to mutations in the alpha-spectrin gene, the beta-spectrin gene, or the band 3 gene.