[Incidence of thalassemia in Switzerland]

A total of 2672 cases with thalassemia syndromes observed in the period from 1 January 1968 to 30 April 1974 are classified according to type of thalassemia and the patient's country of origin. During the past 15 years some 10 patients annually with classical heterozygous beta-thalassaemia have been found to be of purely Swiss origin. Due to increased immigration from Mediterranean countries the Swiss patients represent only 2.6 percent of all cases at the present time, a marked decrease from the earlier 30 percent. Since 1968 2260 cases of thalassemia syndrome have been found in Italian patients. Smaller groups of patients originate from Greece, Spain and Turkey. Homozygous beta-thalassemia was observed in 56 cases. Ranking third among thalassemia syndromes is the Hb Lepore trait found in 16 cases. The increase in thalassemia syndromes due to population migration over the past 10 years has resulted in the finding of rare types in Switzerland: 8 patients with HbS-beta-thalassemia, 2 with HbC-beta-thalassemia, 3 cases of HbH-alpha-thalassemia and 2 cases of Hb Bart's-alpha-thalassemia are reported. The difficulty of diagnosing deltabeta-thalassemia and alpha-thalassemia is emphasized.