In this model series plasmodium positive children where at higher relative risk of mild anemia or worse (Hb < 110 g/L), (RR = 1.28, 95% CI 1.2; 1.36, p<0.001), moderate anemia or worse (Hb < 90 g/L), (RR = 1.76, 95% CI 1.49; 2.08, p<0.001) and severe anemia (Hb < 70 g/L), (RR = 3.01, 95% CI 1.79; 5.1, p<0.001). The gene discussed is GSTM1; the disease is anemia (phenotype).