Sickle cell is the name given to inherited diseases of the blood. However, sickle cell anaemia is the most serious of these illnesses. Those with this form are born with the condition because they have inherited a gene mutation responsible for this anaemia from both parents.
Those who suffer from this disease produce unusually shaped red blood cells that do not survive as long as normal-shaped ones. Apart from developing anaemia, sickle cell sufferers experience episodes of intense body pain, which is caused by the unhealthy red blood cells sticking together and creating blockages in the tiny blood vessels throughout the body. This is often referred to as a sickle cell crisis which needs urgent medical attention.
Painkillers and drugs to lower the numbers of other cells in the blood, such as white blood cells and platelets, can help to reduce some of the complications of sickle cell.
If only one parent is the carrier of the gene for sickle cell anaemia and passes this gene to an infant, then they will go on to develop the sickle cell trait. However, this does not cause illness, and those with sickle cell trait produce mainly healthy red blood cells with few mutated ones. The minority of unusually shaped red blood cells are not enough to cause anaemia, blood vessel blockages, or any other complication related to sickle cell anaemia.
Those with sickle cell trait can have children who will only express the trait but no disease symptoms, as long as only one parent is a carrier of the sickle cell gene. Screening of the partner of a carrier of sickle cell trait is the best way to ensure that they are not also carriers of sickle cell, as this would increase the chances of any offspring developing full sickle cell anaemia.
The only situations where sickle cell trait can lead to health problems are in cases of severe dehydration, intense physical activity with no rest periods in between, and living or exercising at extreme altitudes.
Sickle cell trait is found mainly in certain ethnic groups, and this puts them at risk of passing full sickle cell disease to their children. One in four West Africans and one in ten Afro-Caribbeans are sickle cell trait carriers. Others that have a higher risk of being sickle cell anaemia carriers are Mediterraneans and those from the Middle East, whilst white Europeans are far less likely to be affected.
A possible explanation for certain ethnic groups being affected more by sickle cell anaemia than others around the world can be linked to malaria. Sickle cell trait and disease are prevalent in parts of the world where malaria is a major health hazard.
A sickle red blood cell is unusually shaped and has a stretched membrane that becomes porous, allowing the malaria-causing parasites to feed off the cell nutrients. However, sickle cells do not survive long. The death of the cell removes the nutrient supply to the parasite, causing the death of the parasite as well.
Sickle cell anaemia has no cure; only the symptoms can be treated. It is an inherited disease where a mutated gene must be passed on by both parents to increase the chances of developing full sickle cell anaemia.
Trait carriers can live normal lives with few symptoms, if any. Those with sickle cell trait are most likely to originate from Africa and the Middle East.
Interestingly, those most likely to suffer from sickle cell originate from countries where malaria is rife, leading to theories that sickle cell could be an evolutionary response to protecting the body from the malaria parasite.