English: Sickle cell anaemia (SCA) also called depranocytosis is a genetic blood disorder associated with the circulation of abnormal rigid sickle shaped red blood cells that can potentially occlude blood vessels leading to episodes of pain (sickle cell crisis or vaso-occlusive crisis). This sickling occurs because of a mutation in the haemoglobin gene resulting from substitution of glutamic acid by lysine in the 6 position of the beta chain of the haemoglobin molecule.