Dominant beta-thalassaemia is a form of beta-thalassaemia resulting in moderate to severe anaemia. Prevalence of this form is not known. Presents with moderate to severe anaemia, jaundice and splenomegaly. Rare mutations in the beta-globin HBB gene result in synthesis of extremely unstable beta-globin variants which precipitate in erythroid precursors causing ineffective erythropoiesis.