GSTM1 and anemia (phenotype): Among the children with anemia (n = 39; using altitude adjusted Hb), the majority (56%) had microcytic (MCV < 77 fL, for children 6–35 months and < 79 fL for children 36–59 months), 31% had normocytic (MCV 77–86 fL for children 6–35 months and 79–86 fL for children 36–59 months), and 13% had macrocytic anemia (MCV > 86 fL).