[Sickle cell anemia and malaria--interferences]

Abstract

Usually in a population the frequency of lethal recessive genes decreases by eliminating the homozygous individuals. In sickle cell disease the decrease of the frequency of mutant recessive genes does not take place. The fact that a gene which in the homozygous state expressed a serious clinical picture reaches a high frequency in a population can be explained only by a process of natural selection that would offer the heterozygous an advantage. Starting from the discovery that the territories where malaria is endemic, the hypothesis that there might be a link between these two disease was put forward. The present essay wishes to synthesise the epidemiological studies and the mechanisms of resistance of heterozygous HbS/HbA to malaria formerly described.