Abstract
Using DNA dot-blot hybridization, restriction endonuclease gene mapping with oligonucleotide probes, restriction fragment length polymorphism linkage analysis, and hybridization, prenatal diagnosis was performed for 32 presnancies at risk for α-thalassemia and for 10 pregnancies at risk for β-thalassemia. The DNA samples were prepared from chorion villi or amniotic fluid cells.