[Heterozygous β thalassemia with triplication of the α globin gene].

We describe a case in which the interaction of heterozygosis for the mutation Beta IVSI - 110 G> A and the ααα(anti 3,7) allele was the likely cause of the clinical occurrence of thalassemia intermedia. The proposita, a 19 years old, gypsy, Portuguese woman presented with chronic mild anemia, jaundice and splenomegaly in spite of having the β-thalassemia trait. The analysis of the α-globin gene revealed heterozygosis for α-globin gene triplication with the presence of allele ααα(anti -3.7). This case brings again to discussion the complexity of genetic interactions underlying a phenotype of thalassemia intermedia and stresses the importance of looking for another cause in individuals with beta-Thalassemia minor uncommom phenotype.