Clinical and hematologic aspects of hemoglobin E beta-thalassemia

Hemoglobin E beta -thalassemia is an important cause of childhood chronic d isease in Southeast Asia. It is characterized by the presence of hemoglobin E and F, and the amount of hemoglobin E ranges from 35% to 75%. The patien ts are generally classified as having thalassemia intermedia because they h ave inherited a beta -thalassemia allele and hemoglobin E, which acts as a mild beta (+)-thalassemia. However. a remarkable variability in the clinica l expression, ranging from a mild form of thalassemia intermedia to transfu sion-dependent conditions, is observed. Severe hemoglobin E beta -thalassem ia may have clinical features of thalassemia major. Phenotypes of thalassem ia major can be predicted from the early onset of clinical symptoms and the requirement of regular blood transfusion from infancy for survival. Coinhe ritance of alpha -thalassemia alleviated the severity of beta -thalassemia disease in patients with at least one allele of mild beta -thalassemia geno type. (C) 2000 Lippincott Williams & Wilkins,Inc.