What is Thalassemia?

Thalassaemia is an inherited (genetic) condition affecting the blood. There are different types of thalassaemia. Depending on which type you have, thalassaemia may cause no illness at all, or may be a serious lifelong condition requiring treatment.

What causes Thalassemia?

The cause is an inherited (genetic) change, involving the genes which tell the body how to make an important chemical called haemoglobin. Haemoglobin is the chemical which carries oxygen in the blood – it is the one which gives blood its red colour.

Haemoglobin is made out of different parts. The main parts are called alpha chains and beta chains which are put together to make the haemoglobin molecule. In thalassaemia, part of the haemoglobin is faulty – usually either the alpha chains or the beta chains. This means that some of the haemoglobin does not work properly.

As a result, there is not enough normal haemoglobin and the red blood cells break down easily. This makes the person lacking in haemoglobin (anaemic), with various symptoms. Meanwhile, the body tries to make more haemoglobin and more red blood cells. So, the blood system goes into overproduction mode which can cause more symptoms and complications.

What is Thalassemia trait?

This means that you carry a thalassaemia gene but can still make enough normal haemoglobin. So, you will usually not have any or just relatively mild symptoms or problems from the thalassaemia. You may not know you have it unless you have a special blood test.

Why should we get tested for it?

Worldwide, thalassaemia is one of the most common inherited diseases. However the number of people with thalassaemia is very variable between people from different parts of the world. It is much more common in people from the Mediterranean, Middle East, Central Asia, Indian Subcontinent, Far East and Africa.

The World Health Organization (WHO) estimates that about 3 people in every 200 of the world’s population may be beta thalassaemia carriers.

If you carry the gene for thalassemia trait, your children can inherit the gene. By itself this is not a problem. However, if your partner also has a similar gene, your children might get a double dose of the abnormal haemoglobin gene and could inherit a severe form of thalassaemia which needs life long blood transfusions and treatment.

It is a recommended test for every pregnant woman in India.

How is the screening done?

If you carry beta thalassemia trait gene, you may not know it, however there are certain changes in your blood that can be picked by a blood test known as Haemoglobin electrophoresis.

It is important to note that the screening test does not identify the faulty gene.

What if I test positive for the trait?

Having a beta thalassemia trait does not usually cause any major problem to you in pregnancy.

However if you test positive, it is recommended that your partner is also tested for the same.

A child inherits haemoglobin genes from both parents. For example, if both parents have beta- thalassaemia trait, there is: a 1 in 4 chance of the child having normal haemoglobin genes; a 1 in 2 chance of the child having beta-thalassaemia trait; and a 1 in 4 chance the child will have Beta thalassemia major or Beta thalassemia intermedia which need lifelong treatment and monitoring.

Hence even if both partners carry the beta thalassemia trait gene, there is 75% chance that the baby would not have beta thalassemia major/intermedia.

What if both partners carry beta thalassemia trait?

If both partners have the trait, they would first be evaluated for the type of gene they are carrying. This can then be tested in the developing baby via various invasive testing available. This would be discussed with you.

When is the best time to have a test?​

If you are pregnant, the best time to have a thalassaemia blood test for yourself is before you are 10 weeks pregnant. This allows more time to test your partner or your baby, if needed. You can ask your doctor for a test early in pregnancy, if it is not already offered to you at that time. However, tests can still be done at a later stage.

Do I need to get it tested in every pregnancy?

You can get this test done anytime(even before getting pregnant). It does not need to be repeated again. It is recommended that you have a documented report to show to your doctor.

If you do not have a report, you may be advised to get it done in your pregnancy as it is a part of good routine pregnancy care.