Who is at risk?


It is an inherited disease caused by an abnormal gene.

Sickle cell disease is not contagious. It is an inherited disease. People who have sickle cell anaemia are born with it as it is caused by an abnormal gene. A person must have two copies of the abnormal gene to get the disease. If a person inherits only one defective copy, they are said to have sickle cell trait. Usually, only about 30 per cent of the blood cells of those with sickle cell trait are abnormal. So, except in rare cases, those who have sickle cell trait don't suffer from the disease. They usually don't have problems unless they are in low oxygen environments - such as high altitudes. However, they are carriers who can pass the disease gene on to their offspring. Sickle cell, like some other genetic diseases, is more prevalent in some populations than in others.


In the early part of the 20th Century, scientists who were mostly white and often racially prejudiced, considered sickle cell disease an example of the "hereditary weakness" of the black race. The prevalence of the disease in African Americans was used to support the idea that they were unhealthy and thus inferior to white people. Some of them ignored the fact that white Europeans (such as Greeks) can also suffer from the disease. The scientists of today do not subscribe to these faulty theories of racial superiority or inferiority. It is clear that there are many inherited diseases that are far more common in white races than in others. Cystic fibrosis, for instance, is a hereditary disease that is rare in African and Asian people and common to those of European descent. Phenylketonuria is another disease that is common to people with European ancestry and rare in people with African ancestry. Porphyria is another such disease that is most common to people of Scandinavian, Anglo-Saxon and German ancestors and rare in those of African descent.