A small cohort study of the weekly primaquine regimen in 18 G6PD-deficient (17 had the 871G>A [Viangchan] variant) and 57 G6PD-normal adult vivax malaria patients in Cambodia suggested that single 45 mg doses may not be safe in the more severe G6PD deficiency variants (Kheng et al., 2015). This evidence concerns the gene G6PD and G6PD deficiency.