Contribution of gene conversion in the evolution of the human beta-like globin gene family.

Gene conversion is referred to as one of two types of mechanisms known to act on gene families, mainly to maintain their sequence homogeneity or, in certain cases, to produce sequence diversity. The concept of gene conversion was established 20 years ago by researchers working with fungi. A few years later, gene conversion was also observed in the human genome, i.e. the gamma-globin locus. The aim of this article is to emphasize the role of genetic recombination, particularly of gene conversion, in the evolution of the human beta-like globin genes and further to summarize its contribution to the convergent evolution of the fetal globin genes. Finally, this article attempts to re-examine the origin and spread of specific mutations of the beta-globin cluster, such as the sickle cell or beta-thalassemia mutations, on the basis of repeated gene conversion events.