Prenatal diagnosis of alpha-thalassemia. Clinical application of molecular hybridization.

The technic of DNA-DNA hybridization was used for prenatal diagnosis of a pregnancy at risk for homozygous alpha-thalassemia. Fibroblasts were cultured from amniotic fluid, and the number of alpha-globin genes in the DNA was quantified by hybridization with radioactive DNA complementary to alpha-globin mRNA sequences. As compared to control studies of DNA from patients with alpha-thalassemia syndromes and from unaffected subjects, the results indicated that the fetus had alpha-thalassemia-1. The diagnosis was confirmed by umbilical-cord blood studies.