beta-delta thalassemia

β-δ thal·as·se·mi·a

thalassemia due to a gene that depresses synthesis of both β- and δ-globin chains by the chromosome bearing the abnormal gene. Heterozygous state: thalassemia minor with Hb F comprising 5-30% of total hemoglobin but distributed unevenly among cells, Hb A2 reduced or normal. Homozygous state: moderate anemia with only Hb F present, no Hb A or Hb A2. Synonym(s): F thalassemia