Beta thalassaemia

Published by Bupa's Health Information Team, April 2010.

This factsheet is for people who have beta thalassaemia, or who would like information about it.

Thalassaemia is the name for a group of inherited blood disorders that affect the way red blood cells are produced. It includes alpha and beta thalassaemia, which are different conditions. This factsheet is about beta thalassaemia only.

About beta thalassaemia

The cells that make up your body are controlled by genes - bits of code that tell each cell what to do. Your genes are inherited from your parents.

Haemoglobin is a substance produced by your red blood cells, which gives them their red colour. Its most important function is to carry oxygen to your body's tissues and organs. 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 not present, the structure of your haemoglobin chain is affected.

If you have thalassaemia, it means there is a problem with the structure of your haemoglobin chain and you don't produce enough healthy haemoglobin. If you have beta thalassaemia, it means that production of the beta chain is affected. The effects of the condition depend on how many genes are involved and the severity of the defect resulting from the faulty genes.

People of certain ethnic origins are more likely to get beta thalassaemia. It occurs more often in areas where malaria is common, such as the Middle East, India, South East Asia (including southern China, Thailand and Malaysia), parts of Africa and some Mediterranean countries. Scientists think changes happened in the genes of people in these areas that helped to stop the parasite that causes malaria from multiplying and attacking red blood cells. It's thought that having beta thalassaemia trait may protect you against malaria.

Types of beta thalassaemia

There are three types of beta thalassaemia. These are:

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

Symptoms of beta thalassaemia

The symptoms of beta thalassaemia vary depending on which type you have.

Beta thalassaemia trait

If you have beta thalassaemia trait, you will be healthy and are unlikely to have any symptoms, although you may have mild anaemia.

Beta thalassaemia major

This is a serious condition where your body can't produce enough healthy haemoglobin or red blood cells. Symptoms start to develop between the age of three and six months. These include paleness, shortness of breath and jaundice (where the whites of your eyes and your skin become yellow).

You will also be at risk of:

• your bones not growing properly, possible leading to facial changes
• an enlarged spleen
• leg ulcers
• delayed puberty

You will need life-long treatment with blood transfusions.

Beta thalassaemia intermedia

The symptoms of Beta thalassaemia intermedia vary from one person to another. They are similar to those of beta thalassaemia major but less severe. Some people may have mild anaemia and grow normally while others may need regular blood transfusions to help them grow.

The exact reasons why some people develop beta thalassaemia major and others are able to produce enough haemoglobin to manage without intensive treatment aren't fully understood at present. Reasons for this may include the following.

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

Complications of beta thalassaemia

If you have beta thalassaemia major, you may need to have repeated blood transfusions. This can lead to you having too much iron in your body (iron overload), which can cause:

• damage to your heart
• damage to your liver
• diabetes
• your skin to become grey
• arthritis

Causes of beta thalassaemia

Beta thalassaemia is an inherited condition. If you inherit two faulty genes, one from each of your parents, you will have beta thalassaemia major or intermedia.

If you inherit a single faulty gene from one of your parents, you will have beta thalassaemia trait. If you have beta thalassaemia trait, it's possible that your children will inherit the trait (there is a one in two chance).

If both you and your partner have beta thalassaemia trait, there's a risk that your children may have beta thalassaemia major or intermedia. There is a one in four chance of each of your children having thalassaemia major.

Diagnosis of beta thalassaemia

Beta thalassaemia can be diagnosed with a blood test, which measures the size of your red blood cells and the amount and type of haemoglobin they contain. Red blood cells in someone with beta thalassaemia are paler and different in shape to those of someone without the condition. This is because they contain less haemoglobin.

If you think you might have beta thalassaemia trait, speak to your GP. He or she will be able to give you more information on getting tested and genetic counselling.

Your GP may refer you to a haematologist (a doctor who specialises in conditions of the blood) for tests.

If you or your partner become pregnant and you both have beta thalassaemia trait, you will be offered genetic 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 or she has inherited.

Tests during pregnancy

There are three tests that can be done on a baby before birth to find out whether he or she has a serious type of beta thalassaemia.

• Chorionic villus sampling (CVS) - a sample of the placenta is taken by inserting a needle, either through the wall of your abdomen (tummy) or through a tube placed in your vagina. The sample contains exactly the same genes as your baby and can be taken early in pregnancy.
• Amniocentesis - a sample of the amniotic fluid that surrounds your baby is taken by inserting a needle through the wall of your abdomen.
• Fetal blood sampling - a sample of blood is taken from the umbilical cord. This test is usually only done if the placenta can't be reached easily or if previous tests haven't been able to produce a clear result of your baby's genes.

Treatment of beta thalassaemia

If you have beta thalassaemia major or a severe form of beta thalassaemia intermedia, you will need regular blood transfusions, probably every two to four weeks, to make sure you have enough haemoglobin.

Blood transfusions can have side-effects, the most serious of which is having too much iron in your body (iron overload). Too much iron can damage the organs of your body, including your heart and liver. You will need to take medicines called iron chelators to get rid of the excess iron. These bind to the iron, and it's then removed from your body in your urine or faeces.

The most effective iron chelator is given as an infusion, either under your skin (subcutaneous) or into a vein (intravenous) over many hours. Medicines that you take by mouth are now becoming more widely available as an alternative. 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, meaning less haemoglobin is available for the rest of your body.

The only way that beta thalassaemia can be cured is with a successful stem cell transplant. This is a major procedure that involves transferring bone marrow cells from a healthy person, or stem cells from umbilical cord blood into your body. Stem cells are the most basic type of cell, from which all types of cells in the body develop.

Stem cell transplants 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 transplantation and whether it would be suitable for you.

Living with beta thalassaemia

Beta thalassaemia and its treatment can be frustrating and tiring. You may find it helpful to contact local support groups, who can put you in touch with other people who have beta thalassaemia and their families.

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.