GSTM1 and anemia (phenotype): Among those who were anemic, 110 (28.1%) and 35 (9%) had mild (Hb 11–11.4 g/dl for children age from 6 to 11 years and 11–11.9 g/dl for children age from 12 to 14 years) and moderate (Hb 8–10.9 g/dl) anemia respectively.