Posted by: Glow-worm PJ13 JUN 2012
In 2006, the United Nations passed a resolution designating 19 June as World Sickle Cell Day, with the aim of raising awareness of sickle cell disease, which is one of the world’s most lethal genetic diseases. It is hoped that better access to education and treatment will lead to a reduction in mortality from malaria and the risk of HIV infection, both complications associated with sickle cell disease.
Sickle cell disease is caused by a genetic defect producing an abnormal type of haemoglobin called haemoglobin-S, which alters the shape of red blood cells, especially in conditions of low oxygen concentration, causing the cells to become crescent, or sickle-shaped. The abnormally shaped cells deliver less oxygen to the tissues, and are more likely to become stuck in smaller blood vessels, breaking into pieces and interrupting blood flow. The sickle cells are broken down after only 20 days compared with 120 days for normal red blood cells, causing pressure on folic acid levels.
The disease causes chronic pain and fatigue. It affects about 2 per cent of black people of African origin, as well as people of Mediterranean and Middle Eastern descent to a lesser extent.
The sickle cell gene is thought to have evolved only 40,000 years ago, as a defence mechanism against malaria. The early elimination of the sickle cells has the benefit of increasing the survival prospects against the plasmodium parasite. Management is aimed at preventing infections, organ damage and strokes. The condition can also cause sight problems through damage to the blood vessels in the retina.
Treatment consists of courses of antibiotics, oxygen therapy, blood transfusions and analgesics. Folic acid is given as a precaution against deficiency. However, even with improved treatment, life expectancy is still only just over 50 years for sufferers in the UK.