Hematological phenotype of the double heterozygous state for alpha and beta thalassemia.
In this study, we have correlated the hematological phenotype of 56 Sardinian beta o-thalassemia heterozygotes with their alpha-globin genotype as defined by restriction endonuclease mapping. We found that the coinheritance of the deletion of one alpha-globin and, more obviously, two alpha-globin genes tend to normalize the thalassemia-like hematological phenotype commonly associated with the beta o-thalassemia carrier state. On the other hand, the association of the deletion of three alpha-globin genes caused a more severe phenotype. By globin chain synthesis analysis, those beta o-thalassemia heterozygotes with the (-alpha/alpha alpha) alpha-globin genotype had less deficiency of beta-chain synthesis than did those with the normal alpha-globin genotype (alpha alpha/alpha alpha). In heterozygotes with the (-alpha/-alpha) and in those with the (--/-alpha) alpha-globin genotype the imbalance was actually reversed with a mild or marked alpha-chain synthesis excess respectively.
D004247:DNA / Q000235:genetics*; D004262:DNA Restriction Enzymes; D004911:Erythrocyte Volume; D005319:Fetal Hemoglobin / Q000032:analysis; D005796:Genes; D006580:Genetic Carrier Screening; D005914:Globins / Q000032:analysis / Q000235:genetics*; D006443:Hemoglobin A2 / Q000032:analysis; D006801:Humans; D010641:Phenotype; D013789:Thalassemia / Q000097:blood / Q000235:genetics*
D005914:Globins; D004247:DNA; D006443:Hemoglobin A2; D005319:Fetal Hemoglobin; D004262:DNA Restriction Enzymes