GSTM1 and thalassemia: Breakdown of 4,934 fetuses revealed 3,880 (78.6%) at risk for the three severe thalassemia diseases, including β-thalassemia major, Hb E-β-thalassemia, and homozygous α0-thalassemia, 58 (1.2%) at risk for other α-thalassemia diseases, 168 (3.4%) at risk for β+-thalassemia, 109 (2.2%) at risk for high Hb F determinants, 16 (0.3%) at risk for abnormal Hbs, and 294 (6.0%) with no risk of having severe hemoglobinopathies.