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Thalassaemia (thall-a-seem-ee-ah) is a group of blood disorders affecting the production of haemoglobin. Haemoglobin is the part of the blood which carries oxygen around the body.
Thalassaemia is the most common inherited blood disorder (blood disorders passed on from parents to their children). There are multiple forms of thalassaemia. Beta thalassaemia is the most common form of thalassaemia, and it is divided into thalassaemia trait (sometimes called
thalassaemia minor) and thalassaemia major.
Beta thalassaemia is found in people from many countries around the world, but it is more common in people of Mediterranean, Middle Eastern or Asian origin. It is rare in people of northern European origin.
Thalassaemia trait is present at birth, and remains the same for life. Most people with thalassaemia trait do not know they have it, unless they have been diagnosed with a special blood test. The red blood cells of people with thalassaemia trait are smaller than usual, but they do not have an
illness – they are healthy and have no symptoms of disease. However, some of them may have very slight anaemia, which usually does not require treatment.
If someone has thalassaemia trait, they are sometimes called 'healthy carriers of thalassaemia'. Because it is an inherited condition, if your child has thalassaemia trait, they may pass it onto their future children. If your child's future partner also carries thalassaemia trait, then there is a
risk that their future children may be born with thalassaemia major.
Thalassaemia major is a serious blood disease, with signs that begin in early childhood. Children who have thalassaemia major cannot make enough haemoglobin in their blood. This means they have significant anaemia and require regular blood transfusions. They also develop bone abnormalities and
Every year, at least 100,000 children are born in the world with thalassaemia major. Thalassaemia major is sometimes called Mediterranean anaemia, Cooley's anaemia, or homozygous beta thalassaemia.
If your child has thalassaemia major, they may have:
If your child has thalassaemia major, they will be able to live a normal life with ongoing treatment. Treatment involves regular blood transfusions to boost haemoglobin levels in the blood. However, the blood transfusions can lead to an iron overload (a build-up of iron in the blood).
This overload can cause serious side effects, including diabetes, heart failure and liver disease. Medications are available to treat these side effects.
Currently, a bone marrow transplant is the only chance of a cure for thalassaemia major, but the risks are high. The chances of finding a compatible donor are about 30 per cent, and most donors are siblings. This operation is more successful in young children who don't suffer from iron
overload, but transplant complications or even death are always risks of the procedure.
The risks involved mean that bone marrow transplantation is not a viable option for some families, especially given that children with thalassaemia major can lead a normal life with regular treatment.
Genetic research is ongoing in the hope of finding a cure for thalassaemia major.
If you are planning to start a family:
If your child has thalassaemia trait:
If your child has thalassaemia major:
If you want further information about thalassaemia and family planning, ask your doctor to arrange a visit to a genetic counsellor.
What is anaemia?
Anaemia is when people don't have enough haemoglobin in
their blood. There are many different kinds of anaemia. The most common is iron
deficiency anaemia. People with iron deficiency anaemia do not have enough
haemoglobin because they're not eating enough of the foods that contain iron.
When there are problems with the structure of haemoglobin (even when there is
no iron deficiency), this is called thalassaemia. Haemolytic anaemia is another
type of anaemia, where blood cells are destroyed too rapidly.
If my child has thalassaemia, how likely is it they will
pass it onto their future children?
If your child's future partner does not have the
thalassaemia trait, then there is no risk of their children having thalassaemia
major. There is a 50 per cent chance that each child may have thalassaemia
The more important risk is if your child's future partner
also has the thalassaemia trait. Then there is a risk of your grandchildren
having thalassaemia major. In each pregnancy there is a one in four (25 per cent)
chance that their child will have normal blood, a two in four (50 per cent)
chance that the child will have thalassaemia trait, and a one in four (25 per
cent) chance that the child will have thalassaemia major. The chances of having
a child with thalassaemia major remain one in four (25 per cent) with each
If both partners carry the trait, then they
should talk to a genetic counsellor or doctor before starting a pregnancy. With
proper advice and monitoring, it is possible for them to have a healthy, normal
Developed by The Royal Children's Hospital Haematology and General Medicine departments. We acknowledge the input of RCH consumers and carers.
Reviewed July 2018.
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