Frequently Asked Questions
Why do Thalassaemics need frequent blood
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
What is haemoglobin?
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 =
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.