Highest risk group included thalassemia patients with 2 or more of the following criteria: age more than 50 years, suboptimal transfusion pre-transfusion Hb < 7.0 g/dL (currently and in the last 2–3 years), serum ferritin >4000 ng/mL (currently and in the last 2–3 years), one or more comorbidity such as diabetes, cardiac, endocrine, respiratory or hepatic disease, splenectomy with at least one comorbidity (26). The gene discussed is GSTM1; the disease is thalassemia.