A complete blood count (CBC) showed severe anaemia with a Hb level of 5.5 g/dL, a low mean corpuscular volume (MCV) of 46 fL, a low mean corpuscular Hb (MCH) of 14.2 pg, and a high red cell distribution width (RDW) of 20.9%. The gene discussed is GSTM1; the disease is anemia (phenotype).