Thalassaemia is a group of inherited blood disorders that affect haemoglobin, the oxygen-carrying protein inside red blood cells. In thalassaemia, the body makes too little of one of the globin chains needed for normal haemoglobin. This can lead to small red blood cells, anaemia, iron overload, bone changes, enlarged spleen, and other complications depending on severity.
The condition is commoner in people with family origins from the Mediterranean, the Middle East, south Asia, south-east Asia, and parts of Africa, but it can occur in any population.
Haemoglobin Background
Adult haemoglobin is mainly made from two alpha-globin chains and two beta-globin chains. Alpha thalassaemia affects alpha-globin production. Beta thalassaemia affects beta-globin production.
Reduced globin production disrupts red blood cell development and makes cells more fragile. Severe forms cause lifelong anaemia unless treated.
Main Types
The main groups are alpha thalassaemia and beta thalassaemia.
Alpha thalassaemia varies with how many alpha-globin genes are affected:
- Silent carrier status usually causes no health problem.
- Alpha thalassaemia trait may cause small red blood cells and mild anaemia.
- Haemoglobin H disease can cause moderate or severe anaemia.
- Alpha thalassaemia major can cause hydrops fetalis and may be fatal before or soon after birth without specialist intervention.
Beta thalassaemia varies with how much beta-globin is produced:
- Beta thalassaemia trait usually causes no major illness, though mild anaemia and small red blood cells are common.
- Beta thalassaemia intermedia causes a variable degree of anaemia and may need intermittent or regular treatment.
- Beta thalassaemia major is severe and usually needs lifelong specialist care.
Symptoms
Symptoms depend on type and severity. Mild carrier states may be discovered only through blood tests.
More significant thalassaemia can cause:
- Tiredness and weakness.
- Shortness of breath.
- Pale skin.
- Jaundice.
- Poor growth in children.
- Enlarged spleen or liver.
- Bone changes in severe untreated disease.
- Gallstones.
- Reduced fertility in some people.
- Complications from iron overload.
NHS guidance notes that people with serious thalassaemia often develop health problems from a few months after birth, while less severe cases may not be noticed until later childhood or adulthood.
Inheritance and Carrier Status
Thalassaemia is inherited. A child is usually at risk of a serious form when both biological parents carry relevant gene changes.
Carrier status is also called thalassaemia trait or thalassaemia minor. Carriers generally do not develop thalassaemia major themselves. They may have smaller red blood cells and mild anaemia, but this is not the same as iron deficiency anaemia and does not usually need iron unless iron deficiency is also proven.
Carrier testing matters because two carriers may have a child with a serious haemoglobin disorder. Screening in pregnancy is used in England to identify couples at risk.
Diagnosis
Diagnosis may involve:
- Full blood count.
- Blood film.
- Ferritin and iron studies to separate thalassaemia trait from iron deficiency.
- Haemoglobinopathy screen.
- Genetic testing, especially for alpha thalassaemia or family planning.
- Family testing where appropriate.
Thalassaemia is often detected during pregnancy screening, newborn screening, investigation of anaemia, or family testing.
Treatment
Treatment depends on severity.
Mild carrier states may need no treatment. More severe disease may require specialist haematology care, regular blood tests, and monitoring for complications.
Treatment for serious thalassaemia can include:
- Regular blood transfusions to treat and prevent severe anaemia.
- Iron chelation therapy to remove excess iron from transfusions or increased absorption.
- Folic acid in selected cases.
- Treatment of endocrine, bone, liver, heart, or fertility complications.
- Spleen management where enlargement causes problems.
- Stem cell or bone marrow transplant in selected patients with a suitable donor.
GOV.UK patient information states that people with thalassaemia major often need transfusions every 3 to 5 weeks and lifelong chelation to manage iron overload.
Outlook
Severe thalassaemia used to be fatal early in life for many patients. Modern transfusion, chelation, monitoring, and specialist care have greatly improved survival and quality of life. The condition can still be serious, especially where iron overload, heart disease, infection, endocrine disease, or access to care is a problem.
See Also
References
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