Understanding sickle-cell disease
Red blood cells contain a protein called haemoglobin which picks up oxygen from the air in the lungs and carries it around the body. People with sickle-cell disease have an altered form of haemoglobin, which tends to join together in long strands when it is not carrying oxygen. These strands of altered haemoglobin give the red blood cells their 'sickle' shape. Sickle-cell disease affects people who inherit two copies of the gene that makes the altered haemoglobin.