Bollywood film star Amitabh Bachchan is living with it. So are retired French footballer Zinedine Zidane and former tennis player Pete Sampras. All three are carriers of a genetic blood disorder known as thalassaemia.
In the human body, red blood cells contain haemoglobin, made up of protein chains called alpha-globin and beta-globin.
In thalassaemia, there is a problem in the formation of alpha-globin or beta-globin chains. This leads to your red blood cells not being formed correctly and not being able to carry oxygen.
“Thalassaemia occurs when these protein chains are not formed properly because of missing or altered genes,” explains Dr Angeline Lai, Head and Senior Consultant, Genetics Service, Department of Paediatrics, KK Women's and Children's Hospital.
There are two types of thalassaemia – alpha and beta – depending on which haemoglobin chain is affected. In alpha-thalassaemia, one or more of the alpha-globin genes are affected. In beta-thalassaemia, one or both of the beta-globin genes are affected.
Who’s at risk?
There are two major risk factors for thalassaemia:
Thalassaemia is an inherited condition. So if your parents have faulty haemoglobin genes, they may pass them on to you. Those who get faulty haemoglobin genes from only one parent are called carriers, and they usually have no other signs of thalassaemia other than mild anaemia.
But those who inherit faulty genes affecting the same globin chain from both parents may have moderate to severe forms of thalassaemia. Dr Lai advises: “Those who have a family history of thalassaemia and are planning to have children are advised to have thalassaemia screening. This may include genetic testing, which involves extracting and analysing DNA from a blood sample.”
Thalassaemia is common in certain populations, e.g. Asian or Mediterranean populations. Locally, 1 in 20 persons is a carrier of thalassaemia.
Signs & symptoms
In people with thalassaemia minor, there may be no symptoms at all. “Silent carriers of alpha-thalassaemia typically do not show any signs or symptoms,” explains Dr Lai. “This is because haemoglobin works normally when the lack of alpha-globin chains is minor.”
However, those with alpha- or beta-thalassaemia traits may have mild anaemia.
In thalassaemia intermedia or major, the signs and symptoms may include:
- Poor appetite
- Pale and listless appearance
- Yellow discolouration of skin
- Shortness of breath
Dr Lai adds: “In beta-thalassaemia major, signs and symptoms of anaemia are usually observed in babies within the first two years of life. There could also be other health problems such as slow growth, delayed puberty, and bone problems.”
No treatment is needed for thalassaemia minor, that is, people who are thalassaemia carriers.
More severe cases, however, may require either one or a combination of the treatments given below.
- Blood transfusions: This is the main treatment for patients with thalassaemia intermedia or thalassaemia major. This form of treatment regularly infuses the body with healthy red blood cells that have normal haemoglobin.
- Iron chelation therapy: Frequent blood transfusions can lead to a build-up of iron in the blood which might lead to damage in the liver, heart and other parts of the body. Iron chelation therapy can help to remove excess iron from the body.
- Folic acid supplements: This B vitamin helps to build healthy red blood cells. Your doctor may advise that you take folic acid supplements to boost the number of healthy red blood cells in your body.
KKH runs the National Thalassaemia Registry. The registry provides free genetic counselling for thalassaemia patients and subsidised screening for their family members, at $15 each.