HBB and sickle cell disease: Sickle cell disease (SCD) is a group of life-threatening inherited disorders (sickle cell anemia, sickle cell-hemoglobin C disease, and the sickle cell-β-thalassemias) caused by changes in the gene that encodes hemoglobin subunit beta, a component of the oxygen carrying hemoglobin protein of the red blood cells [1,2].