beta thalassaemia
Last reviewed 06/2021
The beta thalassaemias are a group of diseases characterised by deficient synthesis of the beta-globin gene on chromosome 11.It is inherited as an Autosomal Recessive pattern (except for vary rare 'dominant thalassaemia' mutations) (1).
As a group they comprise the most common inherited disease in the world, affecting about 150 million people or 3% of the world population. The beta thalassaemias are particularly prevalent in the Meditteranean, the Middle East, India, Pakistan and surrounding areas, and the Far East (2). These populations are most affected because they originated in areas of the world where malaria was found and being a beta thalassaemia carrier provides slight protection against malaria.
The carrier incidence of beta thalassaemia in the UK amongst Asian communities is (3):
- 1 in 7 to 1 in 10 for Gujeratis
- 1 in 10 for Sindis
- 1 in 20 for South Indians
- 1 in 25 for Pakistanis
- 1 in 15 to 1 in 30 for Punjabis and Bangladeshis
A national UK guideline re: screening has stated that there is a clinical significant prevalence of beta thalassaemia carriers in all ethnic groups other than Northern Europeans (3).
Reference:
- (1) Standards for the Clinical Care of Children and Adults with Thalassaemia in the UK, United Kingdom Thalassaemia Society 2008
- (2) Ryan K et al. Significant haemoglobinopathies: guidelines for screening and diagnosis. British Journal of Haematology 2010: 149 (1): 35-49
- (3) British Journal of Haematology (1991), 78, 242-7.
haemoglobin synthesis during development
classification by clinical severity or phenotype
classification by molecular genetics or genotype
NHS screening programme for sickle cell and thalassaemia
pre-conceptual screening for haemoglobinopathies
NHS screening programme patient information leaflets for sickle cell disease and thalassaemia