As compared to control patients, aplastic anemia patients had statistically significantly lower mean hemoglobin (Hb) (p<0.001), white blood cell count (WBC) (p<0.001), neutrophil percentage (p<0.001), platelet count (p<0.001), red blood cell (RBC) count (p<0.001) and absolute neutrophil count (ANC) (p<0.001) values, whereas aplastic anemia patients had statistically significantly higher mean lymphocyte percentage (p <0.001), mean corpuscular volume (MCV) (p<0.001) and mean corpuscular hemoglobin concentration (MCHC) (p<0.001) as compared to control patients. The gene discussed is GSTM1; the disease is idiopathic aplastic anemia.