Thalassaemia

What is beta thalassaemia?

Beta thalassaemia is an inherited condition affecting haemoglobin. Haemoglobin is the chemical inside the red blood cells which carries oxygen from the lungs to all body parts. Beta thalassaemia occurs when a person has inherited a gene where they are unable to make enough of the chemical needed for making enough haemoglobin. Beta thalassaemia is just one out of 600 genetic conditions affecting haemoglobin in humans. The word 'thalassaemia' originates from the Greek word 'thalasa' which means the sea.

How do you get beta thalassaemia?

We all inherit many of our characteristics through the genes we take from our parents, for example, the shape of our nose, colour of our eyes, whether we are tall or short and whether we have blond or black hair. Similarly we inherit our haemoglobin type through the genes we get from our parents. We get one haemoglobin gene from our mother and the other from our father. The usual, most common haemoglobin is normal haemoglobin A. If a person inherits two haemoglobin A genes they will have haemoglobin AA (commonly written HbAA). Beta thalassaemia occurs as a result of a person inheriting a beta thalassaemia gene (BThal) from one or both parents.

Beta thalassaemia trait (minor)

Some people inherit one haemoglobin A gene and one beta thalassaemia gene and have beta thalassaemia trait, sometimes called beta thalassaemia minor (commonly written HbABThal). These individuals' red blood cells are a bit paler and smaller than normal red blood cells, they are also a little anaemic, but this anaemia does not usually need treatment. However, they can pass on the beta thalassaemia gene (BThal) to their children.

For example, if both parents with beta thalassaemia trait (HbABThal) have a child, there is a 1 in 4 chance of the child inheriting the usual haemoglobin combination (HbAA), a 2 in 4 chance of the child inheriting beta thalassaemia trait (HbABThal) and a 1 in 4 chance of the child inheriting beta thalassaemia disease, commonly called beta thalassaemia major (HbBThal). Beta thalassaemia major is a serious blood disease.

Who gets beta thalassaemia?

Beta thalassaemia is seen most commonly in people who originate from areas of the world where malaria is or was common. This includes, Mediterranean Islands, Asia, Middle and the Far East. Because of migration and intermarriage it is also seen in other parts of the world including England. For example, 1 in 7 Greeks, 1 in 12 Turks, 1 in 10-20 Asians, 1 in 50 Blacks and 1 in 1000 English Caucasians have beta thalassaemia trait.

What is beta thalassaemia major?

Beta thalassaemia major is the most serious of the beta thalassaemia diseases and occurs when a person has inherited the beta thalassaemia haemoglobin genes from both parents (one from each parent). If both parents pass on a beta thalassaemia gene (BThal) to one or more of their children, the affected children will have beta thalassaemia major (HbBThal).

There are other forms of beta thalassaemia disease and these can be mild or as serious as beta thalassaemia major. For example, if one parent passes on a beta thalassaemia gene (BThal) and the other parent passes on another unusual haemoglobin gene, such as haemoglobin E, the child will inherit haemoglobin E beta thalassaemia (HbEBThal) disease. Haemoglobin E beta thalassaemia can be mild or it can be as serious as beta thalassaemia major.

What happens if a person has beta thalassaemia major?

People with beta thalassaemia major are unable to make the chemical needed for producing enough mature haemoglobin. Haemoglobin is essential for carrying oxygen (air) around the body. Without sufficient haemoglobin the body cannot carry oxygen (air) properly and after a while the body will not survive.

The symptoms of beta thalassaemia major usually start when a child is about three to six months old. The infant starts to lose weight, have difficulty with keeping food down, starts vomiting, has diarrhoea, gets infections easily, fails to thrive and appears generally unwell.

Individuals are very anaemic, especially if they are not given blood transfusion or they are due for their next transfusion. They will appear pale, feel tired and lethargic, breathless and have difficulty with minimum physical activity. There may be yellowing (jaundice) of the eyes and skin due to excessive breakdown of red blood cells. Growth may be delayed, especially if they are not well managed or have not followed the doctors instructions for their treatment.

With good medical care some of these symptoms can be prevented or treated.

What is the usual treatment for beta thalassaemia major?

To be able to live, people beta thalassaemia major need regular blood transfusions, about every four to six weeks right through their life. Without this regular blood transfusion people with beta thalassaemia major cannot live very long and usually die before the age of ten years. But with regular blood transfusion they do very well and live into adulthood.

What other treatment is given?

People with beta thalassaemia major still absorb iron from the food they eat, they also get iron from the blood transfusion, so they have too much iron in the body, this is called 'iron overload'. To get rid of this excess iron they are given a special drug called 'desferal' which helps their body get rid of the excess iron through the urine and faeces. This drug has to be injected under the skin, about five nights a week, through a special pump which takes about six to eight hours to go through. They usually use the pump during the night whilst they are asleep.

They are also give extra vitamin C which helps the desferal to work even better at getting rid of the excess iron. Because they are also prone to infection they may be given other medications to help fight infection.

Isn't blood dangerous?

People who need regular blood transfusions may worry about the risk of infections. Some infections can be passed on through blood transfusion but this is very rare, especially in countries like the UK where all donors and donated blood are tested rigorously to make sure that they are free from infection.

Hepatitis, a disease of the liver caused by a large number of viruses, is one of the most common infections which can be passed on through blood transfusion. All blood donors are tested for this and a wide range of other infections including Acquired Immune Deficiency Syndrome (AIDS). If the test is positive the donor can no longer give blood.

To be extra safe people with beta thalassaemia major are also given the hepatitis B vaccination, to protect them against the most common hepatitis virus.

Will iron tablets help?

Although beta thalassaemia causes an 'anaemia' it is not the same as iron deficiency anaemia. In iron deficiency anaemia there is lack of iron in the body. People with beta thalassaemia disease have excess iron in the body, therefore, giving iron tablets or tonics can make this worse.

Normal red blood cells are mature before they get released from the bone marrow into the blood circulation. Beta thalassaemia red blood cells are not mature enough when they get released into the blood circulation. Therefore, they are very weak, fragile, cannot carry oxygen very well and because they are so fragile they cannot cope with the knocks and bumps they get in the blood circulation and become damaged. Because of this thalassaemia red blood cells only live a few hours in circulation before they get destroyed. This short life span of these immature red blood cells is what causes the anaemia, not lack of iron.

Giving iron tablets or tonics can do more harm than good and is not recommended unless a special blood test has proven the person is genuinely lacking in iron and the medication is prescribed by their doctor.

Is there a cure for beta thalassaemia disease?

Yes. It is called Bone Marrow Transplantation (BMT). Bone marrow is obtained from a matched unaffected brother or sister or unrelated donor and transplanted to the person with beta thalassaemia disease. It is best done when the child is very young. This treatment has been given successfully to many people world wide. However, this treatment is not without side effects and the physical, emotional and psychological effects can be just as distressing as living with the disease.

How can families help?

The most important part a family can play is to learn as much as possible about beta thalassaemia major so that they can give support and encouragement to the person growing up and living with beta thalassaemia disease. The psychological and emotional stress of living with beta thalassaemia major can be reduced if individuals and families try to live as normal a life as possible, whilst coping with the demands of the disease.

Getting involved with local support groups and voluntary organisations is also a practical way of helping people with beta thalassaemia major. The United Kingdom Thalassaemia Society is a national voluntary organisation based in London and offers information, advice, and provides a forum for individuals, families and communities to give and receive mutual support. This organisation also acts as a lobby group to ensure that services are provided for people with beta thalassaemia major nationwide.

Where can I get more information?

There are 37 specialist sickle cell and thalassaemia centres / services in the UK. They are generally funded by the NHS and run by specialist nurses, doctors and social workers. These centres offer information, advice, education of the public as well as educate health, allied and other professionals. They offer free testing and counselling to the general public and support to individuals with thalassaemia and their families in hospital and community settings.

© EMIS and PIP 2004   Updated: April 2004   Review Date: May 2005   CHIQ Accredited