Previous studies reported that monocytosis is associated with hemolysis and inflammation in sickle cell anaemia, however, the influence of carrying different HBB genotypes (6GAG > 6G TG) on the severity of major haematological abnormalities and correlation of haematological parameters with HBB genotypes (6G AG > 6G TG) [12,29]. This evidence concerns the gene HBB and sickle cell disease.