HBB and sickle cell disease: Sickle cell disease (SCD) is a genetic disorder, which is caused by mutation of the hemoglobin subunit beta gene (HBB), most commonly seen in African descendants(Diallo, Tchernia 2002; Kato, Piel, Reid, Gaston, Ohene-Frempong, Krishnamurti, Smith et al. 2018).