| A form of beta-thalassemia characterized by splenomegaly and petechiae, moderate thrombocytopenia, prolonged bleeding time due to platelet dysfunction, reticulocytosis and mild beta-thalassemia. Prevalence of this form is not known. The disorder is not associated with mutations in the HBB gene (11p15.5), but with mutations in the gene encoding GATA-binding protein-1 (GATA1; Xp11.23) that result in reduced expression of the beta-globin genes. Transmission is X-linked. |