[Thalassemia and sickle-cell disease in Norway].

BACKGROUND: Thalassemia is common in the Mediterranean countries, the Middle East, parts of India and South East Asia, with the prevalence of mutations reported to be 2.5-15%. Sickle-cell anaemia is endemic primarily in central parts of Africa, but it also appears in the thalassaemia areas. The purpose of this study was to establish the prevalence of beta-thalassaemia, alfa-thalassaemia and sickle-cell anaemia in Norway. MATERIAL AND METHODS: A questionnaire was sent to 149 departments of paediatrics, gynaecology and medicine in Norway. We asked for numbers registered in 1996 and 1997 of beta-thalassaemia and alfa-thalassaemia with subgroups, and sickle-cell anaemia. RESULTS: The number of patients with thalassaemia was 44 (0.001%) in 1996 and 48 in 1997. In 1996 there were 28 patients with beta-thalassaemia minor, three with intermediary and five major, and six patients with alfa-thalassaemia minor and one with major. In 1996, ten patients were registered with sickle-cell anaemia; in 1997, fifteen patients. INTERPRETATION: The numbers of patients with thalassaemia major or sickle-cell anaemia probably reflect the true prevalence of these diseases. However, for thalassaemia minor and sickle-cell anaemia trait the numbers appear to be too low, as most of these patients do not contact a hospital. The appearance of these diseases in Norway is closely related to immigration from endemic areas.