Sickle cell anemia is caused by homozygosity of the beta-S allele located on chromosome 11p15.5, which differs from the wild type beta-allele by a single nucleotide polymorphism Rs334(T:T) where GTG (Val) is substituted for GAG (Glu) in the sixth codon of the beta-globin gene [2,3,4,5], thus forming a mutated hemoglobin tetramer HbS in the red blood cells of patients with sickle cell anemia [6,7]. Here, HBB is linked to sickle cell disease.