DNA analysis for antenatal diagnosis of thalassaemia and haemophilia.

: Two years' experience with DNA analysis for the antenatal diagnosis of thalassaemia and haemophilia is described. The advantages of DNA testing, including a first-trimester diagnosis and greater availability, must be considered in relation to the problems that are associated with this procedure. In particular, the risk of recombination in DNA polymorphism studies should be understood and explained fully to the patient.