Sickle cell anemia (SCA) is the most prevalent and serious genotype of SCD, followed by HbSC (“mild” form of SCA), hemoglobin (Hb) Sβ thalassemia, HbSβ+thalassemia (accounting for some 30–40% of SCD patients), and other rare and benign genotypes [9,10]. The gene discussed is GSTM1; the disease is Schnyder corneal dystrophy.