What is thalassaemia?Thalassaemia is an inherited (genetic) blood disorder that affects the body's ability to make healthy haemoglobin, the iron-rich protein found in red blood cells. Haemoglobin is needed to carry oxygen to all parts of the body, and carbon dioxide to the lungs to be exhaled.
Are there different types of thalassaemia?There are many types of thalassaemia. The symptoms and severity depend on how many genes have mutated, and which part of the haemaglobin is affected.
Haemoglobin is made up of two matching chains of proteins: the alpha chain and the beta chain. The two main types of thalassaemia are:
- Alpha thalassaemia, which is caused by a mutation of up to four genes (NHS Choices 2010). This mostly affects babies of African, Asian or Middle Eastern descent (Cheerva 2011).
- Beta thalassaemia, which can be caused by more than 200 gene mutations (Cao and Galanello 2010), and is much more common than alpha thalassaemia.
Babies with ancestors from Mediterranean countries, the Middle East, Asia or Africa are most likely to have it (Cao and Galanello 2010, NHLBI 2010). In the UK most cases are in families of Indian, Pakistani or Bangladeshi origin (NHS Choices 2010).
- Thalassaemia minor, which is caused by inheriting the thalassaemia genetic disorder from only one parent. Babies with thalassaemia minor are carriers of the disease, but don't usually have health problems. Beta thalassaemia minor is the most common thalassaemia, and affects about 210,000 people in England (NHS ANSP 2011).
- Thalassaemia major are more serious blood disorders which affect babies who have inherited the defective gene from both parents. Beta alpha thalassaemia has many gene variants that can be carried by parents, so the nature of the condition varies (Streetly et al 2001). Sadly, a number of babies with alpha thalassaemia major do not survive beyond pregnancy or birth (NHS Choices 2010).
How do babies get thalassaemia?Thalassaemia is passed down through families and is carried on a recessive gene. This means that your baby won't automatically inherit the disorder, just as he may not share your or your partner's eye or hair colour.
If your baby has one parent with thalassaemia minor, he has a 50 per cent chance of inheriting the gene defect and being a carrier like his parent. If both your baby's parents have thalassaemia minor, he could have a double dose of the gene and have the more severe thalassaemia major.
However, it's more likely that a baby will be born healthy and be either a thalassaemia carrier or be completely free of the disorder.
Each child born to parents who are both thalassaemia carriers has a:
- one in four chance that they will be neither carriers nor have the disease
- one in two chance of being a symptom-free carrier
- one in four chance of having the more severe thalassaemia major
(NHS Choices 2010)
What are the symptoms of thalassaemia?If your baby is born with alpha or beta thalassaemia minor, he should still grow up to be healthy, and will not usually show any symptoms of having it.
If he has alpha thalassaemia HbH disease (three mutated alpha chain genes), your baby may start to have symptoms of anaemia in his first year. Most children are only mildly or moderately affected, and don't need treatment (Galanello and Cao 2011).
However, severe cases, if left untreated, can cause anaemia, enlargement of the spleen, and may affect how your child's facial bones develop (Cheerva 2011, Galanello and Cao 2011).
Alpha thalassaemia major (Hb Bart's syndrome) is the most severe form of the disease, as the baby's body can't make any normal haemoglobin. Sadly, babies who have this usually die before or shortly after birth from abnormal levels of fluid collecting in their body (hydrops fetalis) (Cheerva 2011, Hamdan 2012).
Babies with beta thalassaemia major (Cooley's anaemia) appear to be healthy at birth, but develop symptoms of anaemia as they grow. They become pale, tired and sleepless. In the long term, if untreated, the lack of haemoglobin in their blood can affect their spleen, liver function, bone development and growth (NHLBI 2010).
How is thalassaemia treated?If your baby is born with beta thalassaemia major or severe alpha thalassaemia HbH disease, regular blood transfusions will help him to grow. He'll be able to do all the things that other children can do (Cheerva 2011, Galanello and Cao 2011, NHLBI 2010). In addition, he may need to take folic acid supplements to help build healthy red blood cells (Galanello and Cao 2011, NHLBI 2010).
Over time, iron from blood transfusions will build up in his body. This can cause complications with his liver, heart, bones and development. Medication called chelation therapy will reduce the amount of iron in his blood (Cao and Galanello 2010, Galanello and Cao 2011, NHLBI 2010). He will be given this by injection or by taking pills.
Thalassaemia treatments are increasingly able to improve the quality and length of life of people with beta thalassaemia major and severe alpha thalassaemia HbH disease (Cao and Galanello 2010, Galanello and Cao 2011, NHLBI 2010). The earlier your baby has treatment the better it will be in terms of his symptoms, side-effects and life expectancy (TIF nd).
Is there a cure for thalassaemia?Beta thalassaemia major can sometimes be cured by a bone marrow transplant from a matching donor (Cao and Galanello 2010, NHS Choices 2010), usually a brother or sister. However, bone marrow transplantation is a painful, risky procedure, and a suitable donor may not be available (NHS Choices 2010).
Blood containing stem cells from the placenta or umbilical cord taken at the birth of a sibling (Cao and Galanello 2010, NHS Choices 2010) may also be used as a cure for thalassaemia.
However, there's no reliable cure for alpha thalassaemia major. Blood transfusions of stem cells to the baby during pregnancy have been tried, but this is complex therapy, with a low success rate (Galanello and Cao 2011).
How do I find out if my baby has thalassaemia?You will be offered a blood test to see if you are a carrier of thalassaemia. If the blood test is positive, your partner will also be invited for testing. The risk of your baby inheriting the condition can then be assessed (NHS NSP 2012).
Diagnostic antenatal tests, such as chorionic villus sampling (CVS) or amniocentesis can detect whether your baby has inherited the condition, and to what extent (NCCWCH 2008, NHS NSP 2012).
If you missed the blood test, and didn’t have any diagnostic tests during pregnancy, you may need to wait and see if your baby develops symptoms.
Unlike sickle cell disease, newborn babies are not routinely tested for thalassaemia. This is because the blood test is not very reliable in the first six months (NHS Choices 2010). However, some types of thalassaemia can be picked up during this screening (Streetly et al 2011).
It won't harm your baby to wait and see. Symptoms of thalassemia usually start to show in the first year or two. At this point, your baby can have a blood test to see if there is a problem and start treatment, if he needs it (NHS Choices 2010).
Where can I get help and support?If you or your baby are tested for thalassaemia you'll be offered genetic counselling. You will be given all the information you need, so you can make informed decisions for you and your baby (Cao and Galanello 2010, Galanello and Cao 2011, NHS Choices 2010).
As being a carrier of thalassaemia is relatively common, there are a few support groups that can offer you support and information. See Thalassaemia International Federation, UK Thalassaemia Society and Cooley's Anemia Foundation.
You can also chat to other parents about thalassaemia in our community.
Cao A, Galanello R. 2010. Beta-Thalassaemia. Gene Reviews. Online: 17 Jun www.ncbi.nlm.nih.gov [Accessed August 2012]
Cheerva AC. 2011. Alpha thalassaemia. eMedicine. emedicine.medscape.com [Accessed August 2012]
Galanello R, Cao A. 2011. Alpha-Thalassaemia. Gene Reviews. Online: 17 Jun www.ncbi.nlm.nih.gov [Accessed August 2012]
Hamdan AH. 2012. Pediatric hydrops fetalis. eMedicine. emedicine.medscape.com [Accessed August 2012]
NCCWCH. 2008. Antenatal care: routine care for the healthy pregnant woman. National Collaborating Centre for Women's and Children's Health, Clinical guideline. London: RCOG Press. www.nice.org.uk [pdf file, accessed August 2012]
NHLBI. 2010. What are thalassaemias? US Department of Health and Human Services, National Institutes of Health, National Heart, Lung and Blood Institute. www.nhlbi.nih.gov [Accessed August 2012]
NHS ANSP. 2011. Beta Thalassaemia major. [Accessed August 2012]
NHS Choices. 2010. Thalassaemia. NHS Choices, Health A-Z. www.nhs.uk [Accessed August 2012]
NHS NSP. 2012. Screening tests for you and your baby. National Health Service, National Screening Programme. www.screening.nhs.uk [pdf file, accessed August 2012]
Streetly A, Dormandy E, Connell P, Wilson J. 2011. Screening for Sickle Cell and Thalassaemis. sct.screening.nhs.uk [Accessed August 2012]
TIF. nd. What is thalassaemia? Thalassaemia International Federation. www.thalassaemia.org.cy [pdf file, accessed August 2012]