G6PD and G6PD deficiency: The prevalence of G6PD deficiency in an endemic region of the Brazilian Amazon has been estimated to be between 3.4 and 5.6% in adult males, with the majority being of moderate activity associated to the A-genetic variant and a small proportion of severe deficiency associated with the Mediterranean variant.46 Although there was strong evidence of the deficient status being protective to malaria infection, individuals with reduced G6PD activity reported a higher incidence of jaundice and blood transfusion when presenting malaria, probably due to primaquine-induced hemolysis.