[Iron overload in a beta thalassemia heterozygote of the intermediate type in a subject of Alsation origin. Results of iron chelation treatment].

Heterozygous beta thalassaemia with microcytic anaemia (hemoglobin concentration 77 g/l) has been recognized in a 49 year-old woman of Alsatian extraction. A long history of microcytic anaemia had led to inadequate oral iron treatment before the patient was referred to us because of the persisting microcytic anaemia and iron loading. Indeed the patient also had haemosiderosis with a high transferrin saturation (73%) and markedly elevated ferritinaemia (1,114 micrograms/ml). Ferrokinetic data showed increased plasma iron turnover, early transfer of iron to the liver and evidence of ineffective erythropoiesis. She was treated with desferrioxamine (3 g every three days subcutaneously) and serum ferritin levels gradually decreased together with transferrin saturation. After 15 months serum ferritin and transferrin saturation were within the normal range. Several hypotheses are discussed to explain why this patient had haemosiderosis associated with heterozygous beta thalassaemia. The propositus was found to be HLA-A3, which is strongly associated with idiopathic haemochromatosis. Her sister also carries HLA-A3 with heterozygous beta thalassaemia but she has neither anaemia nor iron overload. Thus double heterozygotism is unlikely in our patient.