GSTM1 and thalassemia: Hemoglobinopathy is characterized by a reduction in globin production (called thalassemia) or by the presence of an abnormal Hb, such as HbS (Sickle cell hemoglobin; α2βS2), which results from a single base mutation of the β-globin gene at codon 6, leading to an amino acid change from glutamine to valine [11].