A 12‐year preventive program for β‐thalassemia in Northern Sardinia

From 1980 to 1991, 6.3% of the adult population of the province of Sassari, Northern Sardinia, underwent voluntary β‐thalassemia screening. Of the 28 000 subjects examined, 15.7% proved to be heterozygotes for β‐thalassemia. In addition, the screening of 7500 students in 26 villages in Sassari province fixed the frequency of β‐thalassemia in this part of Sardinia at 10.4%. Of the 539 couples at risk to be expected from this figure, the screening detected 43% (234). The data suggest that inductive screening played a major role in the efficiency of this preventive β‐thalassemia program. Follow up of 221 pregnancies found to be at risk for homozygous β‐thalassemia and referred to the Antenatal Diagnosis Service, Cagliari, Southern Sardinia, showed that antenatal diagnosis was carried out in 80% of them. The overall percentage of couples refusing antenatal diagnosis was 10.8%, but over the years the acceptance rate for the procedure increased from 87% to 96%. Atypical hematological findings in 1.5% of 468 members of the couples at risk required globin chain synthesis and molecular analyses to define the precise β‐thalassemia genotype. Heterogeneous “mild”β‐thalassemia mutations as well as coexisting δ‐thalassemia were found in silent type I and type II β‐thalassemia carriers which, without chain synthesis and DNA investigations, would have escaped detection.