Sickle Cell Disease
Sickle cell disease is a disorder affecting the structure of haemoglobin, the red pigment in our blood cells responsible for the transport of oxygen and carbon dioxide. The defect means that the blood cells are less malleable, because the abnormal haemoglobin precipitates when the levels of oxygen are reduced. The abnormal blood cells block small blood vessels, causing pain and breathing problems - called sickle-cell crisis. This is transmitted as an autosomal recessive disease, and it is common in Africa and parts of the Mediterranean. Those who have only one defective gene are said to have sickle cell trait. This confers some protection against malaria, which is why the gene is common in Africa.
|
