Abnormal laboratory results: Screening for thalassaemia.

The thalassaemias are the commonest single gene disorders in the world's population and are a common cause of hereditary anaemia. They should be suspected in any individual who has reduced red blood cell indices. A full blood examination and haemoglobin electrophoresis are the tests which should be used first to investigate a suspected carrier of a thalassaemia gene. Iron deficiency can confuse the interpretation of test results, so iron studies are also often required. DNA analysis may be needed to detect the carrier state, particularly in carriers of alpha-thalassaemia.