Positively Selected G6PD-Mahidol Mutation Reduces Plasmodium vivax Density in Southeast Asians

International audienceGlucose-6-phosphate dehydrogenase (G6PD) deficiency—the most common known enzymopathy— is associated with neonatal jaundice and hemolytic anemia usually after exposure to certain infections, foods, or medications. Although G6PD-deficient alleles appear to confer a protectiveeffect against malaria, the link with clinical protection from Plasmodium infection remains unclear. We investigated the effect of a common G6PD deficiency variant in Southeast Asia—the G6PD-Mahidol487A variant—on human survival related to vivax and falciparum malaria. Our resultsshow that strong and recent positive selection has targeted the Mahidol variant over the past 1500 years. We found that the G6PD-Mahidol487A variant reduces vivax, but not falciparum, parasite density in humans, which indicates that Plasmodium vivax has been a driving force behind the strong selective advantage conferred by this mutation