What is Sickle Cell Disease (SCD)?
Sickle cell disease (SCD) is a collective name for a series of serious inherited chronic conditions that can affect all systems of the body. It is one of the most common genetic conditions in the world and affects around 1 in 2,000 of all babies born in England (Streetly et al. 2010, J Clin Pathology). These sickle cell disorders are associated with episodes of severe pain called sickle cell painful crises. People with sickle cell disorder have a type of haemoglobin (called haemoglobin S (HbS) or sickle haemoglobin) which differs from normal adult haemoglobin (haemoglobin A or HbA). This can cause red blood cells to change shape and become blocked in the blood vessels, causing acute pain. Many systems of the body can be affected meaning that different key organs can be damaged and many different symptoms can occur in many different parts of the body. The main types of sickle cell disorder are sickle cell anaemia, haemoglobin SC disease and sickle beta-thalassaemia. Despite its name sickle beta-thalassaemia is a sickle cell disorder and is distinct from beta-thalassaemia major described below. Read more about the history of sickle cell disease.
What is Beta-Thalassaemia Major?
Beta-thalassaemia major is a serious inherited blood condition in which the red blood cells are nearly empty of haemoglobin, the key part of the blood that carries oxygen around the body. The first life-saving step of treatment involves having blood transfusions every 3-4 weeks for the rest of their lives. This extra blood introduces extra iron into the body that the body cannot get rid of easily. The second step of treatment involves drugs that get rid of the excess iron. Depending upon the individual’s suitability for particular drugs some may take these orally, either by tablet or in a drink, whilst others may have to have injections that are delivered slowly over 10-12 hours, 5-7 days a week. Some young people with SCD, identified by screening as being at high risk of a stroke, may also be on regular blood transfusions and drugs or injections to reduce iron in the body. For both thalassaemia major and SCD attendance at regular hospital outpatient clinics, attendance for regular blood transfusions and attendance for treatment may all impact on school attendance.
How can the symptoms of SCD be prevented?
Certain factors have been identified as more likely to precipitate a painful sickle cell crisis. These include infections, cold and/or damp conditions, pollution, dehydration, strenuous exertion, stress, sudden changes in temperature, alcohol, caffeine, and smoking. Advice to people living with a sickle cell disorder on preventing crises includes keeping warm, eating healthily, taking moderate exercise, taking plenty of fluids, seeking medical advice if they have a fever, avoiding smoking and alcohol, keeping up to date with medications and vaccinations, and trying to live a stress free life.
How does someone get sickle cell disorder (SCD) or beta-thalassaemia major?
Sickle cell disorders and beta-thalassaemia major are inherited, that is passed on through the family. They are not infectious diseases and cannot be caught like coughs or colds. Sickle cell or thalassaemia carriers are sometimes referred to as having sickle cell/thalassaemia trait. Carriers have a normal and an affected gene. In the case of sickle cell carriers their red blood cells contain both normal haemoglobin (adult haemoglobin, haemoglobin A) and sickle haemoglobin (haemoglobin S). Carriers are usually perfectly healthy themselves, and may not know they have trait unless they have a blood test. If someone is a carrier it cannot turn into sickle cell disorder or beta-thalassaemia major. For example, if both partners are sickle cell carriers (haemoglobin AS), then in each pregnancy there is a one in four chance that they could have a child with sickle-cell anaemia (haemoglobin SS, a type of sickle cell disorder); a one in four chance of a child with normal haemoglobin (haemoglobin AA), and a one in two chance of a child who is a sickle cell carrier (AS).
Registry and Surveillance System for Hemoglobinopathies (RuSH) pilot project
Free materials provided by the CDC’s Division of Blood Disorders: State-specific information on sickle cell disease and thalassaemia collected as part of the RuSH project.