G6PD and malaria: Considering that the Duffy-negative blood group is a well-documented protection factor against P. vivax malaria and that there is also evidence that G6PDd protects against P. vivax (Louicharoen et al., 2009; Leslie et al., 2010; Santana et al., 2013), it is possible to consider that the co-occurrence of the G6PD variant and the FY*BES allele in polymorphic frequencies in the “Trombetas Blacks may confer greater protection against malaria in this population.