Different severity of homozygous β-thalassemia among siblings

Abstract

Different degrees of severity of anemia are presented in three siblings with homozygous β-thalassemia. II-1, the most severely affected one, is splenectomized and needs frequent blood transfusion, while II-4 has mild anemia and never receives transfusion. II-3 has moderate anemia and mild jaundice and hepatosplenomegaly. Restriction endonuclease DNA mapping revealed the α-thalassemia-2 genes in II-3 and II-4 and no α-thalassemia-2 haplotype in II-1. Furthermore, II-4, who is mildly affected, is homozygous for α-thalassemia-2 whereas II-3 is an α-thalassemia-2 heterozygote. These observations indicate that concomitant inheritance of α-thalassemia can decrease the severity of β-thalassemia. © 1987 Springer-Verlag.