“Haldane hypothesis”: premises of the Italian epidemiological observations and research on Thalassemia and Malaria

The first demonstration that a specific human disease, malaria, might have a selective role in the evolution and therefore modify the genetic composition of a population by favouring certain genotypes rather than others, came from Anthony Allison’s research on sickle cell anemia in east Africa in 1954. Nevertheless, the first studies aimed at explaining the singular association between hemoglobinopathies and malaria were carried out in Italy since the 1920s. These studies tried to determine the possible origin of the high frequency of thalassemia in certain malarial areas of the country, and if the cause could possibly be, as later hypothesized by J.B.s. haldane in 1949, an advantage of the thalassemic condition due to the concomitant presence of malarial infection. The story of the “malaria hypothesis”, also known as the “haldane hypothesis”, has been pieced together by several authors. Possibly for linguistic reasons, less is known of several premises of the hypothesis of a causal relationship between malaria and thalassemia, from the stand-point of the epidemiological observations and research carried out in Italy. This paper intends to contribute to filling this persistent historiographic void.