Alpha Thalassemia
A disorder characterized by reduced synthesis of the alpha chains of hemoglobin. The severity of this condition can vary from mild anemia to death, depending on the number of genes deleted. A hemoglobinopathy with two clinically significant forms: hemoglobin Bart hydrops fetalis (deletion of all 4 alpha-globin genes; --/--) which is severe and often results in neonatal death; and hemoglobin H disease (most commonly caused by deletion of 3 alpha-globin genes; --/-alpha) which results in hemolytic anemia, splenomegaly and bone changes.