HBB and stroke disorder: The prevalence of overt stroke (9%) in children with SCD of southwestern origin and its absence in children of eastern origin is consistent with what was previously reported in Saudi Arabia [13] and could be due to genetic differences between the two groups. There are two different haplotypes of the beta-globin gene in this country [1]: “Arab-Indian” (AI) in eastern and “Benin” in southwestern patients with SCD [14].