Inheriting sickle cell anaemia disorder
There are certain inherited blood conditions that mainly affect people of African, Caribbean, Mediterranean, Middle Eastern or Asian origin.
These conditions are called haemoglobin disorders, and the most well known are sickle cell disorder (SCD) and beta thalassaemia major.
Sickle cell disorder affects between 12,500 and 15,000 people in the UK, making it the most common inherited disease in the country. It evolved thousands of years ago in areas of the world where malaria was common.
Sickle cell disorder is a group of conditions. The most serious (and common) is sickle cell anaemia. Most people affected by sickle cell anaemia are either of African or Caribbean origin.
Read more about thalassaemia.
What is sickle cell anaemia?
Sickle cell anaemia affects red blood cells. Healthy red blood cells are disc-shaped, flexible and move easily through blood vessels. They contain a protein called haemoglobin, which helps carry oxygen around the body.
In people with sickle cell anaemia, the haemoglobin doesn't work properly and turns red blood cells into crescent (sickle) shapes. These can get stuck in blood vessels and block the blood flow.
How do you get sickle cell anaemia?
People are born with sickle cell anaemia, inheriting it genetically from their parents.
If both parents have the gene for sickle haemoglobin, there is a:
- 1 in 4 chance the child will have sickle cell anaemia
- 2 in 4 chance the child will carry the gene but have no symptoms - this is known as being a carrier, or having sickle cell trait
- 1 in 4 chance the child will not carry the gene
If only one parent has the gene for sickle haemoglobin, there is a 1 in 2 chance the child will carry the gene for sickle haemoglobin. The child will not have sickle cell anaemia.
Testing for sickle cell anaemia
A simple blood test will show whether a person is a carrier of the sickle cell gene.
In England, all pregnant women are offered screening for sickle cell anaemia (either a blood test or a questionnaire) to find out if they are a carrier.
If a pregnant woman is a carrier, the baby's father should be offered a screening blood test. There is also screening to find out whether an unborn baby has sickle cell disorder.
All newborn babies are offered a test for sickle cell disorder as part of the routine newborn blood spot test.
Men and women should find out if they are a carrier before they start a family so they have time to get information and find out what choices they can make. Talk to your GP for more information and advice.
What are the symptoms?
Symptoms of sickle cell anaemia vary from person to person. Common symptoms include:
- episodes of pain (known as a crisis) caused by blood cells getting stuck in the blood vessels - the pain can be in the bones, joints, stomach and chest
- swollen hands and feet - often the first sign of sickle cell anaemia in babies
- chronic anaemia - low iron levels in the blood, which makes you feel tired and out of breath; people with sickle cell anaemia should not take extra iron, as their bodies can't cope with it
- jaundice - yellowing of the skin and eyes because the liver can't get rid of dead sickle cells
- damage over time to the heart, lungs and liver
People with sickle cell anaemia can be more vulnerable to infections, such as pneumonia. They therefore may be offered a daily dose of penicillin to protect them against this.
Sickle cell crises in children need to be treated under medical supervision (a GP or hospital) because of the risk of infection.
Adults can treat a mild sickle cell crisis at home by keeping warm and taking painkillers, such as paracetamol. If over-the-counter painkillers don't help, your GP can prescribe something stronger.
If you can't manage the pain at home or you have a fever, you may need hospital treatment. This might include:
- strong painkillers
- intravenous fluids
- blood transfusion
Preventing a crisis
People with sickle cell anaemia can help prevent a crisis by following healthy lifestyle advice that applies to everyone:
- eat a healthy, balanced diet
- exercise regularly - talk to your GP first, as you should avoid getting tired or seriously out of breath
- don't smoke - get help to stop smoking
- drink alcohol sensibly
In addition, people with sickle cell anaemia should avoid:
- getting too hot or cold, as extremes in temperature can trigger a crisis
- getting dehydrated (not drinking enough water)
- doing activities in an environment where there's less oxygen, such as scuba diving, mountain climbing or having an anaesthetic
People with sickle cell anaemia and sickle cell carriers should be careful when having an operation under anaesthetic. They should make sure the anaesthetist (or dentist, if it's a dental procedure) knows about their condition or carrier status.
Read more about:
Article provided by NHS Choices
Record managed by Oxfordshire Family Information Service