The thalassemia syndromes: molecular basis and prenatal diagnosis in 1990.

In this review I have outlined the molecular basis and prenatal diagnosis of alpha-thalassemia and then concentrated on the state of our knowledge of the molecular basis of beta-thalassemia and its prenatal diagnosis. I discussed the improved but more complicated genetic counselling now available as a result of our increased knowledge of the effects of various defects in the beta-globin gene. Our knowledge of the heterogeneous molecular basis of the thalassemia syndromes has become very impressive and it is hoped that effective therapy will soon follow. For the present, however, prevention of the birth of affected children is the most effective means of reducing the suffering associated with the thalassemia syndromes, and prevention of this type is succeeding in many parts of the world, including North America.