Mujica-Coopman et al. [9] reported among children 19 to 72 months of age, prevalence of anemia (4%) in Chile and Costa Rica (anemia defined as a Hb concentration of less than or equal to 10.0 g/dL or ferritin levels below 12 μg/L, respectively). The gene discussed is GSTM1; the disease is anemia (phenotype).