- A congenital hemolytic anemia caused by defects of the erythrocyte membrane, enzyme deficiencies, or hemoglobinopathies.
- A familial congenital hemolytic anemia characterized by numerous abnormally shaped erythrocytes which are generally spheroidal. The erythrocytes have increased osmotic fragility and are abnormally permeable to sodium ions.
- An autosomal dominant inherited disorder characterized by the presence of smaller than normal, sphere-shaped erythrocytes. It results in hemolytic anemia and splenomegaly.
- Autosomal dominant trait marked by splenomegaly, jaundice, and fragile, spheroid erythrocytes which are prematurely cleared by the spleen; anemia is usually mild; treatment is splenectomy.
- Hemolytic anemia due to various intrinsic defects of the erythrocyte.
- Includes hereditary erythrocyte membrane defects, enzyme deficiencies, hemoglobin abnormalities, stem cell defects (paroxysmal nocturnal hemoglobinuria), and alloimmune (rh) disease of newborn.