SCD is a hereditary hematological disorder characterized by dysfunctional sickle Hb (HbS) caused by a single point mutation that replaces glutamic acid at the sixth position of the Hb β-globin gene with valine (β6 Glu→Val; Bunn, 1997 ▸; Steinberg, 2008 ▸). This evidence concerns the gene GSTM1 and Schnyder corneal dystrophy.