An increase in primaquine dose of 0·1 mg/kg was not associated with a decrease in haemoglobin concentration of more than 25% alongside moderate-to-severe anaemia (haemoglobin <10 g/dL) by day 7 across age groups, transmission settings, and in patients with normal or unknown G6PD activity (table 5, appendix pp 24–26). The gene discussed is G6PD; the disease is anemia.