The mean (±SD) Hb A2 proportions in the normal and genetically proven beta thalassemia heterozygotes were 2.70 ± 0.40% and 6.30 ± 1.23%, respectively, as determined by Q-Sepharose micro-column chromatography, and 2.65 ± 0.31% and 5.37 ± 0.96%, respectively, as determined by HPLC. The mean Hb E proportions in the Hb E heterozygotes were 23.25 ± 4.13% and 24.72 ± 3.5% as determined by Q Sepharose micro-column chromatography and HPLC, respectively. In the large-scale survey for beta thalassemia, 23 at risk couples were detected. Seven affected fetuses were identified by prenatal diagnosis.