Sickle cell disease

Sickle cell disease is caused by a gene problem that is inherited from your parents. It is not something you can catch, and it is not caused by anything the parents did during or before pregnancy.

Inheriting sickle cell disease

You inherit one set of genes from your mother and one from your father. Genes always come in pairs. Children born with sickle cell disease inherit a copy of the sickle cell gene from both of their parents, so each one of the pair of genes is faulty.

This happens when both parents are "carriers", meaning they carry the faulty gene for sickle cell. This is also known as having the sickle cell trait.

Carriers do not have sickle cell disease, but if their partner is a carrier too, they may have a child with the condition.

When both of a child's parents are sickle cell carriers:

• there is a 25% (one in four) chance that each of their children will not inherit any faulty genes. They will not have sickle cell disease, and they will not be able to pass it on to their children
• there is a 50% (one in two) chance that each child will inherit a copy of the faulty gene from just one parent and be a sickle cell carrier
• there is a 25% (one in four) chance that each child will inherit copies of the sickle cell gene from both of their parents and have sickle cell disease when they are born

You can find more information about how sickle cell disease is inherited from the Sickle Cell Society.

Learn more about sickle cell carriers and screening

A blood test can be done at any time to find out whether you have sickle cell disease, or whether you are a carrier who could have a child with the condition.

Sickle cell disease is usually picked up during pregnancy. In Scotland, every pregnant woman is offered free screening to find out whether her baby is at risk of having the condition. Even if your family background does not make it likely that your child will have sickle cell disease, you can still ask for a test. Where possible, screening should be done before the tenth week of pregnancy. This leaves time to think about further tests that can show whether your baby will be born with sickle cell disease.

Newborn babies are also screened for sickle cell disease as part of the newborn blood spot test, known as the heel prick test. There are a few reasons for this:

• If the baby's parents were not screened during pregnancy, this test shows whether the child has sickle cell disease.
• If screening during pregnancy showed the baby had a high risk of sickle cell disease but no further testing was done, the heel prick test will settle whether the child has the condition or not.
• The test shows whether the baby is a carrier of sickle cell, meaning they could one day have children of their own with the condition. You can find out more about sickle cell carriers here.
• The heel prick test also identifies other inherited conditions, such as cystic fibrosis.

If the heel prick test suggests that the baby could have sickle cell disease, another blood test will be used to confirm the diagnosis.

Learn about being tested to see if you carry the sickle cell gene.

Sickle cell disease carriers and screening

Sickle cell disease carriers are people who carry the faulty gene that causes sickle cell disease but do not have the disease themselves. This is also called having the sickle cell trait. If you have the sickle cell trait, you will not develop sickle cell disease. However, there is a risk that you will have a child with the condition, or a child who is also a carrier.

Sickle cell disease carriers

Anyone can carry the sickle cell gene, but people from certain ethnic backgrounds are much more likely to be carriers. You are more likely to be a carrier if you have family from one of these areas:

• Africa
• Asia
• The Caribbean
• The Eastern Mediterranean
• The Middle East

Most sickle cell carriers in the UK have an African or Caribbean family background. It is estimated that around one in ten people with this background may be a sickle cell carrier.

Finding out if you are a sickle cell carrier

You can ask your GP for a blood test at any time to find out whether you are a sickle cell carrier. This is a particularly good idea if your family background makes it more likely that you have the gene. Both men and women can have the test.

Every pregnant woman in Scotland is offered screening to check whether her baby is at risk of being born with sickle cell disease. You can ask for a test even if your family background does not suggest your child will have the condition. It is also a good idea to have your partner screened for the gene. Where possible, screening should be done before the tenth week of pregnancy, so that there is time to think about further tests that can show whether your baby will be born with sickle cell disease.

Read more about diagnosis and screening for the sickle cell disease gene here.

Other health risks for sickle cell carriers

If you carry sickle cell, you are not at risk of developing sickle cell disease. The only time you may be at risk of health problems is in rare situations where you might not get enough oxygen, such as:

• Having surgery under general anaesthetic. Make sure your medical team know you carry sickle cell before your operation, so they can ensure you get enough oxygen.
• Taking part in extreme sports such as deep sea diving or climbing at high altitude. If you do sports like these, make sure you are never short of oxygen.
• Doing regular, intensive physical activity. Drink plenty of fluids during training and avoid pushing yourself to extreme exhaustion.

There is also a very small risk of kidney problems linked to carrying sickle cell. Apart from these uncommon situations, you can lead a completely normal and healthy life as a sickle cell carrier.

Other blood disorders

Sickle cell carriers are also at risk of having a child with a blood disorder if their partner carries a different type of blood disorder. You can find more detailed information about some of the other types of carrier on the following pages:

• Your baby carries a gene for sickle cell
• Your baby carries a gene for unusual haemoglobin

Please do not include personal information such as your name, location or any personal health conditions.

If you have sickle cell disease, whatever your age, a team of medical professionals at a specialist sickle cell centre will look after you. Together with you, they will draw up a care plan that helps you understand the condition properly and work out the best way to manage it.

Treating and preventing sickle cell crises

Most sickle cell crises can be handled at home. If you or your child is having a crisis, these steps are recommended:

• Ordinary painkillers such as paracetamol and ibuprofen can help. Aspirin should not be given to anyone under 16. If these are not enough, your doctor may prescribe something stronger.
• Place a heating pad or a warm towel on the painful area and gently massage it. Pharmacies usually sell heating pads for this.
• Drink plenty of fluids. Staying hydrated helps.
• Calming distractions like reading, videos and computer games are a good way to take your mind, or your child's mind, off the pain.

If none of this helps, or the pain is very severe, phone your doctor. If you cannot reach your doctor, go to the nearest hospital emergency department. You or your child may need to stay in hospital for a few days to receive stronger pain relief.

The best way to prevent a crisis is to know what tends to set one off and avoid it.

• Prevent dehydration by drinking plenty of fluids, especially water.
• Avoid alcohol, because it dehydrates you.
• Keep warm with enough layers of clothing so you do not get cold, and stay away from extreme temperatures.
• Avoid sudden changes in temperature. Do not swim in cold water, for example.
• The thinner air at high altitude can trigger a crisis, so take care if you are at high altitude for any reason. Flying should not be a problem, because aircraft cabins are pressurised and keep a steady oxygen level.
• Stay active, but avoid anything that leaves you severely out of breath.
• Do not smoke. Smoking can bring on acute chest syndrome.
• Stay as relaxed as you can. Stress can trigger a crisis, so it is worth learning relaxation techniques such as breathing exercises.

If you keep having crises, your care team may suggest a medicine called hydroxycarbamide (also known as hydroxyurea). It is a capsule taken once a day. It works by lowering the number of other kinds of blood cell in the body, such as white blood cells and platelets (the cells that help blood clot).

Because of this, you will need regular blood tests to check that you are staying healthy.

Treating and preventing infections

Children with sickle cell disease should be kept up to date with all their routine vaccinations. They may also need extra ones, such as the hepatitis B vaccine and the yearly flu vaccine.

If you have sickle cell disease, you will most likely need to take a dose of antibiotics every day, usually penicillin. This does not carry any serious health risks.

You can lower your risk in daily life by being careful about anything that makes you more open to infection. Always follow good food hygiene, for example.

If you are planning to travel abroad, speak to your doctor as far ahead as you can. You may need extra vaccinations or medicines, such as anti-malarial tablets if you are going somewhere malaria is a risk. It is also wise to take extra care with food and water.

Treating anaemia

Most of the time anaemia causes no symptoms and needs no treatment. However, children with sickle cell anaemia who are also on a limited diet (a vegan or vegetarian diet, for instance) may need folic acid supplements. Folic acid helps the body make more red blood cells, so it can help improve anaemia.

It is important to understand that this kind of anaemia is not the same as anaemia caused by lack of iron, so do not take iron supplements without first talking to your care team. Taking iron supplements when your anaemia is due to sickle cell disease can be dangerous.

Serious or persistent anaemia may need blood transfusions or hydroxycarbamide.

Treating other sickle cell disease-related issues

There are various treatments for the other problems sickle cell disease can cause, depending on the symptom and how severe it is:

• Acute chest syndrome needs emergency treatment. This means oxygen, blood transfusions, antibiotics and fluids through a vein, and possibly hydroxycarbamide to stop it happening again.
• Painkillers can treat joint and bone pain.
• Children can be given a short course of hormones to start delayed puberty.
• Gallstones are treated by surgery to remove the gallbladder.
• For persistent priapism, medicine can be used to get blood flowing, or a needle can be used to drain blood from the penis.
• People who have had a stroke, or who are at higher risk of one, are given regular blood transfusions or hydroxycarbamide.

There is also chelation therapy, which means taking medicine to bring the level of iron in your blood down to a safe level. This is given to people who need a lot of blood transfusions.

Learn more about living with sickle cell disease here

Getting surgery when you have sickle cell disease

If you are due to have surgery, or you are taken in for emergency surgery, there are some important precautions to take.

Tell your care team about any planned surgery that involves a general anaesthetic.

On the day, tell your surgeon that you have sickle cell disease.

General anaesthetic can cause a number of problems, including raising the risk of a sickle cell crisis. It is important that you are watched closely during the operation, given plenty of fluids and kept warm.

You may need a blood transfusion before the surgery to lower the chance of complications.

Pregnancy and birth with sickle cell disease

You can have a healthy pregnancy with sickle cell disease, but it is a good idea to talk to your care team before planning one, for several reasons:

• There is a higher chance of complications during pregnancy, such as miscarriage, pre-eclampsia, anaemia and sickle cell pain.
• You may need to stop some sickle cell medicines, such as hydroxycarbamide, before getting pregnant, because they can harm an unborn baby.
• It may be worth finding out whether your partner is a sickle cell carrier and talking to a counsellor about what that could mean.
• You may need extra monitoring and extra treatment during pregnancy.

If you are not planning a pregnancy, it is important to use a reliable form of contraception.

Learn about pregnancy and newborn screening for sickle cell disease

Sickle cell disease is a lifelong illness, but with proper treatment and good self-care it can be managed well. Beyond doing your best to prevent symptoms and crises, there are a few things you can do that will make living with the condition easier and help you stay in the best possible health.

The outlook for people with sickle cell disease

Most children with sickle cell disease go on to lead normal, happy lives. Even so, the condition varies a great deal from one person to another, and it remains a serious illness.

Sickle cell disease can have a big impact on a person's life. It can lead to serious infections, strokes and transient ischaemic attacks (TIAs), and lung problems, and these can be fatal.

On the whole, life expectancy for people with sickle cell disease is shorter than normal. However, this depends on the type of sickle cell disease a person has, the problems they experience, and how the condition is treated.

Milder types of sickle cell disease may not affect life expectancy at all. People with sickle cell anaemia typically live to between 40 and 60 years of age. As newer treatments are developed, it is hoped that the outlook will continue to improve.