β-Thalassemia Mutations in Corsica

P-Thalassemia (thal) is one of the most widespread fatal genetic diseases. In the Mediterranean area its frequency reaches considerable levels, with carrier peaks of 15% in Cyprus (1) and 12-19% on the Sardinian (2) islands. There is no definitive cure for this disease, except bone marrow transplantation from HLA-identical donors (3). Nevertheless, allogenic bone marrow transplantation is still associated with a high rate of mortality and/or morbidity. On the other hand, prevention through carrier screening, genetic counseling, and prenatal diagnosis, has been particularly effective. In areas such as Sardinia, where a prevention program has been implemented for several years, the frequency of new P-thalassemic individuals has dropped from 11250 live births to 1/4000 in 1996 (4). Nowadays, prenatal diagnosis is done on fetal DNA using molecular biology techniques to detect thalassemic defects (5-7). Molecular analysis requires the knowledge of the type of molecular lesion carried by the parents. Therefore, an essential prerequisite for prevention is the knowledge of the type and frequency of the P-thalassemic mutation in a defined area. More than 200 mutations affecting the P-globin gene expression have been characterized to date (8). The distribution of the P-thalassemic mutations in the Mediterranean area