ID anemia (IDA) occurs when ID is severe enough to affect hemoglobin (Hb) synthesis and is defined as a Hb concentration below 130 g/L (13 g/dL, 130 mg/mL) in men, 120 g/L (12 g/dL, 120 mg/mL) in nonpregnant women, and 110 g/L (11 g/dL, 110 mg/mL) in pregnant women [6]. The gene discussed is GSTM1; the disease is anemia (phenotype).