In short: Haemoglobinopathies are inherited disorders of haemoglobin, the oxygen-carrying protein in red blood cells. The main types are sickle cell disease and the thalassaemias. They are diagnosed with blood tests such as a full blood count and HPLC or haemoglobin electrophoresis, and carrier testing helps couples understand the risk to their children.
Haemoglobinopathies are inherited blood disorders caused by changes in the structure or production of haemoglobin, the protein in red blood cells that carries oxygen around the body. They are among the most common genetic disorders in the world, affecting millions of people.
What Are Haemoglobinopathies?
Haemoglobinopathies are caused by changes (mutations) in the genes that code for haemoglobin. These changes can alter the structure of the haemoglobin molecule or the amount produced. There are two main categories:
- Haemoglobin variants: Structural changes in haemoglobin, as in sickle cell disease (HbS) or haemoglobin C disease (HbC).
- Thalassaemias: Reduced production of one or more globin chains, as in alpha thalassaemia and beta thalassaemia.
Common Types of Haemoglobinopathies
1. Sickle cell disease (SCD)
- Cause: A change in the beta-globin gene that produces haemoglobin S (HbS), inherited from both parents (or HbS with another variant such as HbC or beta thalassaemia).
- Symptoms: Long-term anaemia, painful crises, a higher risk of infections and organ damage.
- Management: Pain relief, hydroxycarbamide (hydroxyurea), blood transfusions, and bone marrow (stem cell) transplant in selected severe cases.
2. Beta thalassaemia
- Cause: Gene changes that reduce or stop beta-globin chain production.
- Symptoms: Carriers (trait) usually have no symptoms. Beta thalassaemia major causes severe anaemia, and without treatment, bone changes and poor growth. Regular transfusions can lead to iron overload.
- Management: Regular transfusions, iron chelation therapy, and potentially curative bone marrow transplant.
3. Alpha thalassaemia
- Cause: Deletion or change of one or more of the four alpha-globin genes.
- Symptoms: Ranges from no symptoms or mild anaemia in carriers, to HbH disease, to life-threatening hydrops fetalis in the most severe form.
- Management: Depends on severity; may include transfusions and specialist care in pregnancy.
4. Haemoglobin C disease (HbCC)
- Cause: A structural haemoglobin variant (HbC) inherited from both parents.
- Symptoms: Mild anaemia and an enlarged spleen.
- Management: Usually supportive; symptoms are generally mild.
5. Haemoglobin E (HbE)
- Cause: A common structural variant, especially in South-East Asia.
- Symptoms: Usually mild or none; when combined with beta thalassaemia (HbE/beta thalassaemia) it can cause moderate to severe anaemia.
- Management: Depends on severity; may include transfusions.
Diagnosis
- Full blood count (FBC): Identifies anaemia and red blood cell changes.
- Haemoglobin electrophoresis or HPLC: Identifies the types and proportions of haemoglobin present.
- Genetic (DNA) testing: Confirms specific mutations, especially in alpha thalassaemia.
Symptoms
Symptoms vary widely depending on the type and severity:
- Tiredness and weakness
- Shortness of breath
- Jaundice or pale skin
- Delayed growth and development in children
- Frequent infections
- Enlarged spleen (splenomegaly)
Management and Treatment
Treatment focuses on relieving symptoms and preventing complications:
- Blood transfusions: For severe anaemia, particularly in thalassaemia.
- Iron chelation therapy: To prevent iron overload from repeated transfusions.
- Medicines: Hydroxycarbamide for SCD reduces painful crises by increasing fetal haemoglobin (HbF).
- Bone marrow transplant: Potentially curative in selected severe cases. Gene therapies are also emerging.
- Supportive care: Including folic acid, vaccinations, antibiotics where advised, and prompt treatment of infections.
Prevention and Early Detection
- Carrier testing and genetic counselling: Especially important for people with a family history. It helps couples understand their carrier status and the chance of passing a condition on to their children.
- Screening in pregnancy and at birth: In England, all pregnant women are offered screening, and newborn babies are screened for sickle cell disease through the heel-prick test, so treatment can start early.
- Lifestyle: A healthy diet, staying well hydrated, keeping warm and avoiding extreme exertion can help reduce complications such as sickle cell crises.
The Global Impact
Haemoglobinopathies are most common in regions where malaria was historically widespread, such as sub-Saharan Africa, the Mediterranean, the Middle East, South Asia and South-East Asia. With migration, they are now a global health concern, including in the UK.
Further Reading
- Why HPLC is the gold standard for sickle cell and beta-thalassaemia testing
- Understanding hereditary persistence of foetal haemoglobin (HPFH)
- NHS: Sickle cell disease
- NHS: Thalassaemia
Conclusion
Haemoglobinopathies are lifelong conditions, but early diagnosis and good management can greatly improve quality of life. Advances in treatment, genetic counselling and awareness continue to improve outcomes for affected people and their families.
Frequently asked questions
What is the most common haemoglobinopathy?
Sickle cell disease and thalassaemia are the most common worldwide. In England, sickle cell disease is one of the most common inherited conditions.
How are haemoglobinopathies diagnosed?
With a full blood count and HPLC or haemoglobin electrophoresis, sometimes confirmed by DNA testing.
Can carriers have symptoms?
Carriers (trait) are usually healthy. Thalassaemia carriers may have mildly small red cells, which can be mistaken for iron deficiency.
Should I be tested before having children?
If you or your partner have a family history or come from a higher-risk background, testing before pregnancy can help you understand your options.
Book a test at E&J Bio
Walk-ins are welcome at our clinic at 305 Neasden Lane, London NW10 1QR. We are open 7 days a week, including Sundays, or you can book online at ejbio.co.uk/shop. Results for the Blood Group and Sickle Cell Genotype test are usually available the same day.
- Blood Group and Sickle Cell Genotype (AA, AS, SS) (results: same day)
- Haemoglobin Electrophoresis (results: same day)
- Blood Group, Sickle Cell Genotype Plus Thalassaemia Screen - Couple (results: next day)
This article is for general information only. Please discuss your results, and any symptoms, with a doctor or other qualified healthcare professional.
