In the book "Eat Right For Your Type" the author Peter J. D'Adamo writes that the O blood type was the first blood type to appear in humans and affirms that the blood groups are the key to the immune system. Some recent phylogenetic network studies in humans and non-human primates implies that the A gene represents an ancient form of the ABO genes. Relationships between blood groups and infectious and noninfectious diseases and immunodeficiency abnormalities have also been reported in the literature. As D'Adamo's propositions seem to be in opposition with the current knowledge, we present in this paper some comments about the genetics and the evolution of the ABO blood group genes and some links between this blood system and the functioning of the immune system.
ABO system; genetics; polymorphism; immune system