Only one G6PDd individual from Burkina Faso had severe anemia after PQ treatment (Hb concentration of 7 g/dl at day 10); this individual was CYP2D6 EM/UM, had a baseline Hb concentration of 12.5 g/dl, and recovered completely by day 14 (Hb concentration of 11.9 g/dl). The gene discussed is GSTM1; the disease is anemia (phenotype).