Frequently Asked Questions


Why do Thalassaemics need frequent blood transfusions?

The normal lifespan of a red blood cell is 120 days, but in thalassaemics this is shortened. The abnormal production of beta chains means that alpha chains do not have partner chains to pair with in order to make haemoglobin. Excess free globin chains precipitate and damage the red blood cell membrane. The cells eventually lyse, few red blood cells, and little amount of haemoglobin in them induces anaemia. To maintain red cell viability and function, thalassaemics are given blood transfusions. The transfusion of red cells corrects anaemia and makes sure the tissues get a normal amount of oxygen so that the body can grow and function normally.


What is haemoglobin?

Transport of oxygen from the lungs to the tissues is carried out by a highly specialised molecule, haemoglobin, which is contained within red blood cells. Haemoglobin (Hb) consists of two pairs of globin chains.

2 alpha + 2 beta = Hb A
2 alpha + 2 gamma = Hb A2
2 alpha + 2 delta = Hb F

In healthy adults approximately 95% of the Hb is Hb A, <3.5% is Hb A2 and <1% is Hb F.


What is a carrier?

The precise structure of globin chains is encoded by the respective genes. There are two forms 'alleles' of every kind of gene in the body, one inherited from your mother and one from your father. Normal people have two normal genes for haemoglobin synthesis. Sometimes an individual may inherit a defected gene from one parent but a normal one from the other (heterozygote), they are carriers of the trait, however the activity of the normal gene makes enough stable haemoglobin.


Can Thalassaemia be prevented?

Yes. The way to prevent thalassaemia is to prevent the birth of an affected child. Prenatal diagnosis, the ability to detect abnormalities in an unborn child, has been used for over three decades.