GSTM1 and anemia (phenotype): In children between 13 and 17 years, deficiency was 10⋅3 % and anaemia due to deficiency was 15⋅3 % (Hb<120 g/l in women and Hb<130 g/l in men), figures that are considered public nutrition issues(10,12); this situation is common in developing countries(13).