Sickle cell disorders include sickle cell anemia (Hb SS genotype) and sickle cell syndrome, with various combinations of Hb S with other abnormal hemoglobins, including sickle beta-thalassemia syndromes (HbS-β0 thalassemia, HbS-β+thalassemia), hemoglobin SC (HbSC) disorder, hemoglobin SE (HbSE) syndrome, HbS/hereditary persistence of fetal hemoglobin (S/HPFH), and many other rare combinations [6]. Here, GSTM1 is linked to sickle cell disease.