Also known as: Cooley’s Anaemia; Mediterranean Anaemia; Thalassaemia
Thalassaemia major is an inherited blood disorder, which affects the red blood cells and their ability to carry oxygen around the body. Thalassaemia is caused by a mutation in the gene which codes for one of the building blocks of haemoglobin – the oxygen carrying protein contained within the red blood cells. The result of the mutation is that there is a severe reduction in the amount of haemoglobin. Thalassaemia is commonest in people whose family origins are Mediterranean, Asian, South East Asian and Middle Eastern countries.
Medical text written by December 2012, Dr Paul Telfer, Senior Lecturer, Centre for Haematology, Barts and The London, Queen Mary’s School of Medicine and Dentistry, London, UK.
Children with thalassaemia major are healthy at birth but become pale within the first few months of life. They fail to grow and develop normally, are prone to infections, develop enlargement of the bones (particularly facial and skull bones) have an enlarged spleen and liver. Without treatment, they develop severe complications of anaemia (where the amount of haemoglobin in the blood is below the normal level) such as heart failure and do not survive.
The condition is caused by mutations which affect the production of the beta chain of haemoglobin. This results in low levels of haemoglobin.
Thalassaemia major is treatable, and in some cases curable. Treatment consists of regular (usually 3 to 4 weekly) transfusion of red blood cells. This corrects the anaemia and prevents bone deformity. It enables normal growth and development.
Additional treatment is required to control the build-up of iron. Iron build-up (overload) occurs because transfused red blood cells contain iron, and the body does not have an effective natural means of disposing of iron. If untreated, iron overload will cause damage – specifically to the heart, liver and hormone-producing glands. Iron overload is managed with iron removal (chelation) therapy.
There are several drugs available to chelate iron, and for most patients, a long-term chelation regime can be found to control iron effectively. The currently licensed iron chelation drugs are desferrioxamine (given by subcutaneous – under the skin – infusion usually 5 nights per week), deferiprone (orally administered three times per day) and deferasirox (orally administered once per day). Occasionally, a specialist will advise a combination of these drugs.
Many patients can consistently adhere to the prescribed medications, and maintain acceptable haemoglobin and iron levels. They do not develop severe complications, have a good quality of life and a good life expectancy. Those whose adherence is erratic or experience adverse reactions to the chelation medications, may experience complications caused by iron overload, such as growth disturbance, failure of pubertal development, thyroid and parathyroid dysfunction, diabetes, heart and liver problems.
Thalassaemia major can be cured during childhood by a procedure called bone marrow transplantation. This is only possible when there is a bone marrow donor (usually a brother or a sister) who has the same tissue-type (is histocompatible with the patient). Unfortunately, for many patients, a donor is not available.
Autosomal recessive. People who have only one copy of the altered gene (carrier of thalassaemia, thalassaemia trait) are healthy. They need a simple blood test to detect if they are a carrier so they can have appropriate advice about planning a family.
If the mutation in a family is known, molecular testing (testing DNA) of cells obtained from the placenta during early pregnancy either via amniocentesis or chorionic villus sampling will identify if the condition is present in the unborn baby.
UK Thalassaemia Society
The Society is a Registered Charity in England and Wales No. 275107. It provides information and support to children and adults affected by Thalassaemia and their families, and offers counselling services.
Group details last updated December 2014.