DNA haplotype constellations of the beta-globin gene cluster have been analyzed in German families with hemoglobinopathies (Hb Freiburg, Hb Köln, Hb Presbyterian) and beta-thalassemias. The polymorphic patterns obtained were compared to those found in families from Greece, Italy, and Turkey affected by beta-thalassemia syndromes. With the combined analysis of seven restriction site polymorphisms a DNA-diagnostic prediction for additional offspring could be made with an overall frequency of 75% in the four ethnic groups.