Thalassaemia: what it is, symptoms, causes, screening and treatment

Haemoglobin is used by red blood cells to carry oxygen around the body. The NHS says thalassaemia is the name for a group of inherited conditions that affect haemoglobin, so that some of it does not work properly.

There are different types of thalassaemia, divided into alpha and beta thalassaemias. The NHS says beta thalassaemia major is the most severe type, and other types include beta thalassaemia intermedia, alpha thalassaemia major and haemoglobin H disease. It is also possible to be a carrier, which is also known as having the thalassaemia trait.

It is a genetic condition present from birth. It mainly affects people of Mediterranean, south Asian, southeast Asian and Middle Eastern origin.

The NHS says most people born with thalassaemia experience health problems from a few months after birth. Less severe cases may not be noticeable until later in childhood or even until adulthood. If you are a carrier you will usually be healthy and will not have any symptoms.

The two main problems are anaemia and too much iron in the body. Almost everyone with thalassaemia major or other serious types will develop anaemia, which can be life threatening in severe cases.

• Anaemia: tiredness and a general lack of energy, shortness of breath, pounding, fluttering or irregular heartbeats (palpitations), pale skin and sometimes yellowing of the skin and eyes (jaundice).

• Too much iron in the body, usually a side effect of repeated blood transfusions, which can cause heart problems, swelling and scarring of the liver, delayed puberty, low levels of oestrogen or testosterone, diabetes, and thyroid and parathyroid gland problems.

• Delayed growth during childhood.

• Small stones in the gallbladder (gallstones), which can cause inflammation, stomach ache and jaundice.

• Unusual bone growth, such as an enlarged forehead or cheeks, and weak, fragile bones (osteoporosis).

• Reduced fertility, with some people needing fertility treatment to have children.

A carrier carries at least 1 of the faulty genes that cause thalassaemia, but does not have thalassaemia themselves. The NHS says carriers will not develop thalassaemia and being a carrier will not generally cause any health problems. You may get mild anaemia because your red blood cells are smaller than usual and your haemoglobin level may be slightly lower than normal. This is not the same as iron deficiency anaemia and does not need any treatment.

If you are a carrier, you are at risk of having a child with thalassaemia if your partner is also a carrier. The NHS says that even in mild cases there is a risk you could pass on a more serious type to your children.

The NHS says thalassaemia is caused by faulty genes that affect the production of haemoglobin, and that a child inherits them from their parents. It is not caused by anything the parents did before or during pregnancy, and you cannot catch it from someone who has it. The parents of a child with thalassaemia are usually carriers, each having only 1 of the faulty genes.

Genes come in pairs. To be born with beta thalassaemia, a child has to inherit a copy of the faulty gene from both parents. If both parents have the beta thalassaemia trait, the NHS gives these chances for each child:

• 1 in 4 chance of inheriting no faulty genes: the child will not have thalassaemia or be able to pass it on.

• 1 in 2 chance of inheriting 1 copy from 1 parent: the child will be a carrier.

• 1 in 4 chance of inheriting copies from both parents: the child will be born with thalassaemia.

The NHS says thalassaemia is often detected during pregnancy or soon after birth. GOV.UK (NHS England) says all pregnant women in England are offered screening for thalassaemia, and all biological fathers are offered screening if the pregnant woman is a genetic carrier for sickle cell disease or thalassaemia. Some types may be picked up by the newborn blood spot (heel prick) test.

GOV.UK says there are no risks associated with the screening, that it is an individual choice whether or not to be screened, and that it can provide information that may mean families have to make further important decisions. NHS pregnancy guidance says screening is ideally done before 10 weeks of pregnancy but can be done at any time, and that if you carry thalassaemia you are offered further tests and a conversation about your choices.

Blood tests can also be carried out at any age to check for thalassaemia or to see if you are a carrier. You can request a test from your GP surgery or nearest sickle cell and thalassaemia centre.

The NHS says thalassaemia usually needs lifelong treatment with blood transfusions and medicine. Children and adults are supported by a team of healthcare professionals working together at a specialist thalassaemia centre, who work with you on an individual care and support plan. Eating a healthy diet, exercising regularly and not smoking or drinking too much alcohol can also help you stay as healthy as possible.

Most people with thalassaemia major or other severe types need regular blood transfusions to treat anaemia. This is usually done in hospital and takes a few hours each time. How often depends on the type: beta thalassaemia major may need a transfusion about once a month, while less severe types may need them only occasionally.

Transfusions are very safe but cause iron to build up, so medicine to remove it, called chelation therapy, is very important because high iron levels can damage organs. The NHS says there are 3 chelating agents: desferrioxamine (given by a pump over 8 to 12 hours, 5 or 6 times a week), deferiprone (tablet or liquid 3 times a day) and deferasirox (once a day as a tablet).

The NHS says the main health problems of thalassaemia can often be managed with treatment, but it is still a serious condition that can have a significant impact on a person's life. Without close monitoring and regular treatment, the most severe types can cause serious organ damage and be life threatening. In the past, severe thalassaemia was often fatal by early adulthood. With current treatments, people are likely to live into their 50s, 60s and beyond.

If you or your child has thalassaemia, your healthcare team will pass information to the National Congenital Anomaly and Rare Disease Registration Service, which helps scientists look for better ways to prevent and treat it. You can opt out at any time. The NHS names the UK Thalassaemia Society as the main UK charity for people with thalassaemia.

Thalassaemia care in the UK is delivered mainly through NHS specialist centres, since transfusion and chelation programmes need dedicated services and long-term monitoring. Antenatal and newborn screening are NHS programmes. Private haematology can provide diagnostic blood tests, carrier testing and genetic counselling, but ongoing transfusion-dependent care runs through the NHS thalassaemia team.