Sickle cell anaemia is an inherited genetic condition involving an abnormality in haemoglobin (the pigment which carries oxygen in red blood cells). Sickle cell anaemia and sickle cell trait are more common in some racial groups than others. They affect people from the Mediterranean, Africa and the Middle East; it is rare for a white person to have the conditions.

What causes sickle cell anaemia and who can get it?

Sickle cell anaemia is caused by a mistake on a particular gene. Both parents have to pass on the problem gene for there to be a chance of you having sickle cell anaemia. If you inherit the problem gene from one parent, and a normal gene from the other, they will have something called ‘sickle cell trait’, which doesn’t usually cause any symptoms, but can be passed on to the next generation.

Sickle cell anaemia causes problems with the red blood cells. The pigment that makes red blood cells red (haemoglobin) also holds them in shape. Normally they’re doughnut-shaped, but the red blood cells in someone with sickle cell anaemia are crescent or sickle-shaped, (which gives the name to the disorder) which can cause various knock-on effects.

What are the signs and symptoms of sickle cell anaemia?

The crescent-shaped red blood cells can cause various symptoms. The sickle cells don’t live as long as normal red blood cells, which means that there aren’t as many red blood cells circulating in the bloodstream as usual. This causes anaemia, which can make you feel tired and look pale. The sickle cells also clump together more than normal, which can slow down your blood flow. This can cause very painful episodes, called ‘crises’, where the sickle cells get stuck in a blood vessel.

How is it normally diagnosed and treated?

Testing during pregnancy, from 11 weeks can identify the haemoglobin type of the baby.  It’s also simple for adults and children to be screened for sickle cell anaemia. This is done from a blood sample taken from a vein in the arm or from a finger-prick or heel-prick.
 
People with sickle cell anaemia can have a ‘crisis’ in various parts of the body. The pains associated with a ‘crisis’ occur at the site of the ‘crisis’. It could be pain in your bones and joints that gradually gets worse, tummy pain, a high temperatures and even breathing difficulties (if the crisis is in the chest). They will usually need treatment in hospital, with fluids given directly into a vein (intravenously), and oxygen and medicines to take away the pain. If the number of red blood cells is very low, you may need a blood transfusion too. Long-term damage can be avoided if medical treatment is given as soon as a crisis starts.

Can it be prevented?

The condition can’t be prevented, but some babies, especially if they come from the particular racial groups where sickle cell anaemia is more common, are tested for sickle cell anaemia when they are born. This means that crises can be spotted quickly in future, and the bouts of anaemia can be dealt with too. There are plans for all babies to be checked like this in the future.

Looking forward

People with sickle cell anaemia often live a normal life in between crises. If the blood flow problems are severe, there is a risk of organ failure, but this is usually avoided by careful monitoring on a regular basis. As research continues to tell us more about sickle cell anaemia, new treatments will hopefully be discovered, which will improve the outlook for people with sickle cell anaemia.

For more help and information

If you would like to know more about sickle cell anaemia, please ask your doctor or contact the Sickle Cell Society by calling 020 8961 7795 or visiting their website at www.sicklecellsociety.org.

Last reviewed by Great Ormond Street Hospital: 11 May 2006

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