These discrepancies between these different studies on the role of HbF on the overt stroke need further multinational studies on large cohorts of SCA patients coupled to genetic markers and other parameters like G6PD, alpha thalassemia deletions and Hb saturation which can play a role in the complex physiopathology of stroke in SCD (Adams, 2007; Bernaudin, 2008). This evidence concerns the gene GSTM1 and Schnyder corneal dystrophy.