RESUMO
In this work the author examines the epistemological pathway to the study, diagnosis and therapy of b-thalassemia, serious and very frequent genetic disease in the Italian and Sardinian population know to paediatricians since 1925. The author critically explores the historical approaches to the comprehension of the disease, the phenotype characteristics, firstly described in Italy in 1929, and its familiarity, also described from several authors in the same years. The frequency and the variability of the disease in the population were poorly understood, partly because haematology was still under development and partly for the presence in the patients and in the general population of confounding symptoms and diseases. The hereditary transmission according to Mendelian laws was applied only to the study of few phenotype characteristics, in the attempt to limit the familiar transmission from the long surviving patients. For over 50 years the disease was considered lethal and there were not studies on the real efficacy of the available treatments.