These data suggest that the combined approach of using Hb ≤10 g/dL and RDW >15% (sensitivity of 99% and specificity of 90%, positive predictive value of 90.5% and negative predictive value of 98.9%) performs well obviating the need for using expensive biochemical tests for diagnosing iron deficiency anemia in a low resource setting. The gene discussed is GSTM1; the disease is anemia.