GSTM1 and anemia (phenotype): Cut-off values: No anaemia - Hb ≥ 11.0 g/dL; Mild anaemia - Hb 10.0–10.9 g/dL; Moderate anaemia - Hb 7.0-9.9/dL; Severe - Hb < 7.0 g/dL; Iron deficient - Serum ferritin < 30ng/mL; Iron replete - Serum ferritin ≥ 30ng/mL