hematology and oncology
Hereditary Spherocytosis and Hereditary Elliptocytosis
Introduction
Hereditary spherocytosis and hereditary elliptocytosis are congenital red blood cell (RBC) membrane disorders that can cause a mild hemolytic anemia. Symptoms, generally milder in hereditary elliptocytosis, include variable degrees of anemia, jaundice, and splenomegaly. Diagnosis requires demonstration of increased RBC osmotic fragility and a negative direct antiglobulin test. Rarely, patients<45 years with symptomatic disease require splenectomy. (See also Overview of Hemolytic Anemia .) Hereditary spherocytosis(chronic familial icterus; congenital hemolytic jaundice; familial spherocytosis; spherocytic anemia) is an autosomal dominant disease with variable gene penetrance. About 25% of cases are sporadic. Hereditary spherocytosis is characterized by hemolysis of spheroidal RBCs and anemia. Hereditary elliptocytosis(ovalocytosis) is a rare autosomal dominant disorder in which RBCs are oval or elliptical. Hemolysis is usually absent or slight, with little or no anemia except in some homozygous patients (hereditary pyropoikilocytosis). 