Haemoglobinopathies

The haemoglobinopathies are characterized by abnormalities in the production of haemoglobin. They are common. WHO figures estimate that 5% of the world population are carriers for a haemoglobin disorder.

The haemoglobinopathies be subdivided into:

• structural haemoglobin variants:
  • often due to single amino acid substitutions in either the alpha or beta globin chains
  • a common example is the Glu to Val mutation at position six of the beta globin chain in sickle cell disease
    
    
• imbalanced globin chain synthesis - the thalassaemias
  
  
• hereditary persistence of foetal haemoglobin:
  • genetic defects in the switch from foetal to adult haemoglobin synthesis
  • foetal haemoglobin persists into adult life