[Thalassemia intermedia caused by interaction of IVS-1 1(G--A) mutation in the beta-globin gene and heterozygotic triplication in the alpha-globin gene].

Thalassemia intermedia is a clinical entity characterized by moderate, non-transfusional anemia and hepatosplenomegaly. This phenotype can result from different genetic combinations and is sometimes present in patients with only one parent showing the thalasemia minor phenotype. We report here a family with seven members with the thalassemia beta trait, four of them with thalasemia minor and the other three with thalassemia intermedia. The genetic study of patients with thalassemia intermedia revealed the presence of the mutation IVS-1 1(G-->A) in the beta-globin gene and the heterozygous triplication of the alpha-globin gene, an uncommon association in Spain. The interaction of a mutation in the beta-globin gene with triplication of the alpha-globin gene should be considered in the diagnosis and genetic counselling in those patients with thalassemia intermedia and one normal parent.