For example, for infants and young children, the American Academy of Pediatrics recommends universal screening for anemia by measuring Hb concentration at ~1 y of age [11], including exploration of anemia causes [11,12], whereas the Centers for Disease Control and Prevention recommends screening for iron deficiency anemia at 9–12 mo of age, again at 15–18 mo, and then yearly until 5 y of age [13]. The gene discussed is GSTM1; the disease is Iron deficiency anemia.