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Beta thalassaemia

Thalassaemia is the name for a group of blood disorders which includes alpha and beta thalassaemia. These conditions are very different. This factsheet is only about beta thalassaemia.

The only way to get beta thalassaemia is to inherit it from your parents. People of certain ethnic origins are more likely to get beta thalassaemia.

  • About beta thalassaemia
  • Symptoms
  • Causes
  • Diagnosis
  • Treatment
  • Living with beta thalassaemia
  • Further information
  • Sources
  • Related topics

About beta thalassaemia

The cells that make up your body are controlled by genes, which are bits of code that tell each cell what to do. Your genes determine characteristics such as your hair and eye colour. Everyone has different genes (apart from identical twins). You inherit your genes from your parents.

Haemoglobin is produced by your red blood cells and is what gives them their red colour. Its most important function is to carry oxygen to the tissues and organs in your body. Haemoglobin is made up of two parts called the alpha chain and the beta chain. Each chain is produced by several different genes. If something goes wrong and one or more of the genes are faulty or lost, the structure of your haemoglobin will be affected.

If you have any form of thalassaemia, it means there is a problem with the structure of the haemoglobin in your blood because of a fault in one or more of your genes. It may also be that a gene isn't present at all. People with thalassaemia don't produce enough healthy haemoglobin.

The type of thalassaemia that you have depends on which chain is affected. If you have beta thalassaemia, it means that the beta chain is affected. The severity of the condition is determined by how many genes are involved.

Thalassaemia occurs more often in parts of the world where malaria is common. These include the Middle East, India, South East Asia (including southern China, Thailand and Malaysia) and parts of Africa and the southern Mediterranean. It's thought that being more at risk of thalassaemia may protect you from developing malaria.

Types of beta thalassaemia

There are three different forms of beta thalassaemia. These are:

  • beta thalassaemia trait - this is also known as being a carrier for beta thalassaemia
  • beta thalassaemia major
  • beta thalassaemia intermedia

Symptoms

These will vary depending on whether you are a carrier for beta thalassaemia or if you have beta thalassaemia major or intermedia.

Carrier for beta thalassaemia (beta thalassaemia trait)

If you are a carrier for beta thalassaemia, you will be healthy and are unlikely to have any symptoms. It's possible that you will have mild anaemia. Anaemia is a condition where you have too few red blood cells or not enough haemoglobin in your blood. For more information, please see Related topics.

Beta thalassaemia major

This is a serious condition where your body can't produce enough healthy haemoglobin or red blood cells. You will need to have treatment for the rest of your life. Symptoms start to develop between the age of three and six months. These include paleness, shortness of breath and jaundice (a condition when the whites of your eyes and your skin become more yellow in colour). There will also be the risk of:

  • bones not growing properly, leading to possible facial changes and problems with growth
  • an enlarged spleen
  • leg ulcers
  • infections
  • delayed puberty
  • early menopause
  • conditions such as diabetes and osteoporosis
  • possible death in early childhood

These symptoms are caused by the condition itself. You may have other symptoms as a result of iron overload which happens because of the repeated blood transfusions necessary to treat beta thalassaemia. These may include:

  • extreme tiredness
  • infections
  • osteoporosis
  • diabetes
  • your skin having a grey appearance
  • arthritis
  • damage to your heart and liver

Beta thalassaemia intermedia

If you have beta thalassaemia intermedia, you are likely to have similar symptoms to someone with beta thalassaemia major but initially they won't be so severe. However, your condition is likely to get worse with time and at some stage you will probably need to have regular blood transfusions.

The exact reasons why some people develop beta thalassaemia major and others are able to produce enough haemoglobin to manage without such intensive treatment aren't fully understood at present. However, there are two main reasons why this may be.

  • Although you have inherited affected genes from both your parents, these may be able to function well enough.
  • Other genes may work with the affected ones and help them to work better or increase the amount of healthy haemoglobin.

Causes

If you are a carrier for beta thalassaemia, this means you have inherited an affected gene from one of your parents.

If you inherit an affected gene from both of your parents, you will have beta thalassaemia major or intermedia.

If you are a carrier for beta thalassaemia, it's possible that your children may also be carriers for the condition. If both you and your partner are carriers, there is a risk that your children may have beta thalassaemia major or intermedia.

Diagnosis

If you think there is a possibility that you may be a carrier for beta thalassaemia, visit your GP who will be able to give you more information about the condition and getting tested.

It's possible to diagnose beta thalassaemia with a blood test to measure the size of your red blood cells and the amount and types of haemoglobin they contain. When a sample of blood from someone with beta thalassaemia is examined under a microscope, the red blood cells will be smaller and paler than those of someone without beta thalassaemia. This indicates that they contain less haemoglobin.

If you or your partner becomes pregnant and you are both carriers for beta thalassaemia, you will be offered counselling to help you decide whether or not you wish to go ahead with the pregnancy. You will also be offered a choice of tests that can be done on your baby in the womb to see what genes he/she has inherited.

Tests during pregnancy

There are three tests that can be done on a baby before birth to find out whether or not he/she has a serious type of thalassaemia.

  • Chorionic villus sampling (CVS) - this involves taking a sample of the placenta, which contains exactly the same genes as the baby. This is done by inserting a needle either through the wall of the abdomen (tummy) or through a tube placed in the vagina. This test has the advantage that it can be done early in pregnancy and the results are quickly available.
  • Amniocentesis - this involves taking a sample of the amniotic fluid that surrounds the baby by inserting a needle through the wall of the abdomen. For more information, please see Related topics.
  • Fetal blood sampling - this test takes a sample of blood from the umbilical cord. It's not carried out as often as it used to be as techniques such as CVS and amniocentesis have become more advanced. However, it may be done if the placenta can't be reached easily or if previous tests haven't been able to produce a clear result of the baby's genes. Fetal blood sampling can't be done until about the 20th week of pregnancy. Before this time the baby will still be too small for it to be clear where the umbilical cord attaches - the blood sample is taken from this point.

Treatment

If you have beta thalassaemia major or a severe form of beta thalassaemia intermedia, you will need treatment for the rest of your life. The main thing that this will involve is regular blood transfusions, probably every four to eight weeks, to make sure you have enough haemoglobin.

Blood transfusions can have side-effects, the most serious of which is an increased level of iron in your body (iron overload). Too much iron can damage the organs of your body, including your heart and liver. Therefore, you will need to take medicines called iron chelators to get rid of the excess iron. These bind to the iron, which is then lost from your body in urine or faeces.

The most effective iron chelator is called desferrioxamine. However, this has to be given as an infusion, either under the skin (subcutaneous) or into a vein (intravenous) over many hours each week. Oral medicines such as deferasirox (eg Exjade) are now becoming more widely available as an alternative. All these medicines may cause side-effects, but these are less serious than the effects of iron overload. Always ask your doctor for advice and read the patient information leaflet that comes with your medicine.

If your spleen is enlarged, you may need to have surgery to remove it. This is because blood may collect here, resulting in less haemoglobin being available for the rest of the body.

The only way that beta thalassaemia can be cured is by a successful stem cell transplant. This is a major procedure that involves transferring bone marrow cells from a healthy person into someone who has beta thalassaemia.

Alternatively you may receive a transplant of umbilical cord blood which contains many stem cells. Transplant may be an option for some people, but often the risks are greater than the possible benefits. Your doctor can give you more information about stem cell transplants or please see Related topics.

Living with beta thalassaemia

You may find that the treatment for beta thalassaemia and the effect it has on your life is frustrating and tiring. It may be helpful for you to contact local support groups who can put you in touch with other people who have beta thalassaemia and their families. This may make it easier to reduce the impact that the condition has on your quality of life.

Further information

UK Thalassaemia Society

020 8882 0011

Sources

  • Hoffbrand AV, Moss PAH, Pettit E. Essential haematology. 5th ed. Oxford: Blackwell Publishing, 2006
  • Beta thalassaemia intermedia. UK Thalassaemia Society. www.ukts.org, accessed 3 December 2007
  • Beta thalassaemia (major). UK Thalassaemia Society. www.ukts.org, accessed 29 January 2008
  • Chamberlain G, Steer P. Turnbull's Obstetrics. 3rd ed. London: Churchill Livingstone, 2001
  • British National Formulary (BNF). Drugs used in hypoplastic, haemolytic and renal anaemias. BMJ Publishing Group, 2007. 54: 490-491
  • Bone marrow and stem cell transplantation. Leukaemia Research. www.lrf.org.uk, accessed 4 December 2007
  • Stem cell transplantation for thalassaemia. UK Thalassaemia Society. www.ukts.org, accessed 4 December 2007

Related topics

Amniocentesis

Anaemia - a general overview

Bone marrow or stem cell transplantation