The mean ± SD haemoglobin (Hb) concentration was 11.1 ± 0.9 g/dL with 40.0% of children at < 11 g/dL (lower limit of normal Hb in children aged 0.5–4 years25), suggesting that they had anaemia prior to the intervention. The gene discussed is GSTM1; the disease is anemia (phenotype).