Sickle cell anaemia

Sickle cell anaemia (SCA) is a genetic disease which causes the [red-blood cell]?s of a sufferer to be shaped like sickles, insteaed of the normal rounded shape. This causes the cells to become stuck in capillaries? and deprives the body of oxygen.

The sufferers of the illness usually die early because of this lack of oxygen. However, the illness has not died out even though it can only be inherited, and most sufferers die before they can reproduce. This is because carriers of the gene for the illness are resistant to malaria. In areas where this is a problem, such as Africa, people's chances of survival actually increase if they carry SCA. So the illness continues.

The gene responsible for SCA is recessive. If two parents who are carriers have children, there is a 1-in-4 chance of their child developing the illness and a 1-in-2 chance of their children being carriers.