The Molecular Basis of AE-Bart's Disease

AE-Bart's disease is a thalassemia intermedia resulting from the interaction between α-thalassemia and heterozygous Hb E. In this study we analyzed the α-globin genes of 25 patients designated as AE-Bart's disease by starch gel electrophoresis. Twenty-one cases had Hb Constant Spring in addition to Hbs E + A + Bart's, and the remaining four cases had only Hbs E + A + Bart's. DNA mapping revealed the α-globin genotype of α-thalassemia-1/α-thalas-semia-2 in four patients who had Hbs E + A + Bart's, whereas the α genotype of the remainder is α-thalassemia-1/nondeletion α-thalassemia. The nondeletion α-thalassemia is Hb Constant Spring as indicated by starch gel electrophoresis. Hematologic data and hemoglobin analysis showed that Constant Spring-AE-Bart's disease is a more severe clinical syndrome than AE-Bart's disease.