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). The gene discussed is GSTM1; the disease is Stroke.