Hemoglobin E Disease
(See also Overview of Hemolytic Anemia.)
Homozygous Hb E disease (a hemoglobinopathy) causes a mild hemolytic anemia, usually without splenomegaly.
Hb E is the 3rd most prevalent Hb worldwide (after Hb A and Hb S), primarily in Southeast Asian (> 15% incidence of homozygous disease) populations, although rarely in Chinese populations. Heterozygotes (Hb AE) are asymptomatic. Patients heterozygous for Hb E and beta-thalassemia have a hemolytic disease more severe than S-thalassemia or homozygous Hb E disease and usually have splenomegaly.
In heterozygotes (Hb AE), a microcytosis is present without anemia, and target cells can be seen on peripheral blood smear. In homozygotes, a mild microcytic anemia with prominent target cells exists.
Diagnosis of Hb E disorders is by Hb electrophoresis.
Most patients do not require treatment. However, patients with severe disease may benefit from chronic transfusions or splenectomy.