In agreement with evidence that high socio‐economic status is protective of anaemia (Abdel‐Rasoul, El Bahnasy, El Shazly, Gabr, & Abdel‐Aaty, 2015; Ngesa & Mwambi, 2014), belonging to the middle or upper terciles of the HAI was associated with a significant increase in Hb compared with those in the lower tercile of the HAI for adolescents. The gene discussed is GSTM1; the disease is anemia (phenotype).