Feasibility of prenatal diagnosis of beta thalassaemia by DNA polymorphisms in an Italian population.

A feasibility study of prenatal diagnosis of beta thalassaemia in a northern Italian population has been carried out. Twenty-five families have been studied, each consisting of two parents and a homozygous beta thalassaemia child, thus enabling linkage analysis of restriction fragment length polymorphisms (RFLPs) to the normal and the thalassaemic chromosomes. Using seven standard RFLPs, 19/25 families could be offered prenatal diagnosis; inclusion of the recently described Ava II psi beta polymorphism increased this figure to 23/25 (92%) of the families.