What is beta thalassaemia
This section is dedicated to beta (β-) thalassaemia syndromes of which β-thalassaemia major, also known as Mediterranean anaemia or Cooley’s Anaemia, is the clinically most severe one.
THE MAJOR BETA (β-) THALASSAEMIA SYNDROMES ARE:
- β-thalassaemia major
- β-thalassaemia intermedia
- Other rare thalassaemias
Many diseases in humans are caused by abnormalities in the blood and these are categorized according to the component of the blood which is affected: white cell diseases, platelet diseases and red cell diseases.
Haemoglobin disorders or haemoglobinopathies are a group of conditions affecting human blood – more specifically an important substance or protein called haemoglobin contained in the red blood cells, hence the name haemoglobin disorders or haemoglobinopathies.
Haemoglobin is a protein that consists of the alpha (α) and beta (β) parts or chains and which are in turn produced by the α-globin genes and β-globin genes respectively. Hence the diseases caused by haemoglobin abnormality either with regards to its production or its structure are divided into α-chain diseases (or α-globin gene) diseases and β-chain (β-globin gene) diseases. These genes are found on chromosomes 16 and 11 respectively.
Patients with β-thalassaemia major, the most severe form of thalassaemia, cannot make normal adult haemoglobin, which is made up of equal numbers of α- and β-chains, and as a consequence cannot produce normal red blood cells (RBCs). In these individuals, i.e. those with β-thalassaemia major, each red blood cell contains much less haemoglobin, because the β-globin genes are not working or functioning properly and thus do not or produce very small amounts of β-chains. Consequently, there are far fewer red cells than the normal range. This causes anaemia, which is severe in these patients, as shown in the figure below on the right hand side.
Dramatic improvements in the clinical management of thalassaemia major over the last 30 years and particularly over the last two decades have led to an impressive increase in the lifespan and quality of life of patients who can access – afford — and comply (adhere) with treatment regimes, as recommended by international experts in the context of Guidelines and Standards of Care.
Read TIF’s Article on Cross-talk between available guidelines for the management of patients with β-thalassemia major (2013).
Literature Publications on Survival.
The three curves below demonstrate the impressive improvements in survival i.e. life span of patients with thalassaemia (UK, Cyprus and Italy), directly related to the improvement achieved in the clinical management of this disorder over the years.
Survival Curve – UK (Modell et al., 2000
Survival Curve – Italy (Borgna et al, 2004)
Survival Curve – Cyprus (based on data from the national registry, 2009)