Homozygous hemoglobin E (Hb E) disease is a hemoglobinopathy that causes a mild hemolytic anemia, usually without splenomegaly.
(See also Overview of Hemolytic Anemia.)
Hemoglobin (Hb) E is the third most prevalent hemoglobin worldwide (after Hb A and Hb S). It occurs primarily in Southeast Asian populations, although rarely in people of Chinese ancestry. Patients who are heterozygous (Hb AE) are asymptomatic and patients with homozygous Hb E disease usually have mild anemia. Patients heterozygous for Hb E and beta-thalassemia 0 have a hemolytic disease similar to thalassemia intermedia or major and usually have splenomegaly.
In patients who are heterozygous (Hb AE), a microcytosis is present without anemia, and target cells can be found on a peripheral blood smear. In patients who are homozygous, a mild microcytic anemia with prominent target cells exists.
Diagnosis of hemoglobin E disease is by hemoglobin electrophoresis.
Most patients do not require treatment. However, patients with severe disease may benefit from periodic transfusions or splenectomy.
