GSTM1 and anemia (phenotype): A study of 4526 households from 11 governorates in Egypt, recorded anemia in 35.7% of 6816 adolescents (Hb < 12 g/dL), 35.3% of 2620 schoolchildren (Hb < 11.5 g/dL), and 39.6% of 4376 preschool children (Hb < 11 g/dL) [61].