Thalassaemia
Written by:
Dr Lim Pei Shan
Lecturer and Clinical Specialist O&G,
PPUKM
What is thalassaemia?
Thalassaemia is an inborn blood disease that is common in countries with malaria. It is a genetic defect that leads to reduction or no production of one of the proteins that make up haemoglobin.
Haemoglobin is an iron-rich protein which is present in red blood cells. It has the capability to carry oxygen to all parts of our body. It is formed from two proteins – alpha and beta. Hence, in patients with thalassaemia, there is less production of haemoglobin and healthy red blood cells. The end result is anaemia that usually begins in early childhood.
How many types of thalassaemia are there?
There are many forms of thalassaemia. The two main forms are alpha thalassaemia and beta thalassaemia. Alpha thalassaemia minor is the most common thalassaemia inMalaysia.
There are three types of beta thalassaemia and four types of alpha thalassaemia. Beta thalassaemia is divided into minor (trait), intermediate, and major. Alpha thalassaemia is divided into loss of one gene, loss of two genes, loss of three genes and loss of all four genes. When all four genes are missing, it is called Hb Bart’s which is not compatible with life.
What are the signs and symptoms of thalassaemia?
Both alpha or beta thalassaemia minor (thalassaemia trait) is caused by inheriting the genetic disorder from only one parent. Patients with thalassaemia minor do not usually have symptoms or health problems. Their haemoglobin count occasionally may show borderline or slight anaemia. These features will be more prominent during pregnancy. Some of them may require blood transfusion during pregnancy.
Patients with alpha or beta thalassaemia major will have more serious problems such as transfusion dependency. They usually inherit the gene from both parents (NHS Trust 2009). Babies with Hb Bart’s may develop hydrops fetalis (i.e., swelling or accumulation of abnormal amounts of fluid in the foetus or baby). The baby will usually die before (inside the womb) or soon after birth. Patients with beta thalassaemia major usually appear healthy at birth. However, they subsequently develop symptoms of anaemia as they grow up. They look pale, tire easily and sleep less. The disease will affect their spleen, liver function, bone development and growth(NIH 2009).
Do I have thalassaemia?
Thalassaemia runs in the family. If you have a family member with thalassaemia major or trait, there is a possibility that you may inherit the disease.
I don’t have any symptoms. Do I have to check for it?
It is recommended that one should screen for thalassaemia if you are planning to conceive, especially if you or your husband has a family history of the disease. If either you or your husband has thalassaemia, it is even more imperative that the other partner be tested.
The aim of screening is to detect those at risk of having children with a severe version of the disease. Early detection would allow prenatal diagnosis. This may facilitate early diagnosis and treatment of affected children. It also allows the option of terminating the pregnancy in the event of Hb Bart’s. Besides, a positive screening result is useful in initiating screening for your family members, particularly in those planning to conceive.
How can I know if I have thalassaemia?
All you need to do is to request for a blood screening. The clinics under the Ministry of Health or heath laboratories provide this service.
If I have thalassaemia, what should I do during pregnancy?
You are advised to take 5mg of folic acid everyday at the planning of conception and throughout the pregnancy. If you become anaemic during pregnancy, you need to take iron supplements. Oral iron supplements should be enough. However, some women may require blood transfusion during pregnancy. You may consult your obstetrician or haematologist for more information.
If I have thalassaemia, what is my baby’s chance of inheriting the disease?
In beta thalassaemia, if only one parent has thalassaemia trait, there is a 50% chance of the baby inheriting thalassaemia trait. However, if both parents have thalassaemia trait, there is a 25% chance of having a baby with thalassaemia major and 50% chance of having a baby with thalassaemia trait. The inheritance is slightly more complicated for alpha thalassaemia and, again, it depends on the carrier status of the parents. For further details, do discuss this with your doctor.
How can I find out whether my baby has thalassaemia?
An invasive test is needed in order to find out if your baby has thalassaemia. Samples can be obtained from the placenta (chorionic villus sampling). All these procedures carry risk of miscarriage and infection. Talk to your doctor about this.
Does my baby need any treatment if he/she has thalassaemia?
Generally, patients with thalassaemia trait do not require any specific treatment. However, patients with thalassaemia major will need long term blood transfusion that may lead to iron overload. Hence, these patients will need to undergo therapy that removes iron from their body. Bone marrow transplant is one of the options that may cure the disease. However, a matching donor is needed.
