In Southeast Asia, where thalassemia is prevalent, heterozygous carriers of both β-thalassemia mutation and the (-(SEA)) α-globin gene deletion are encountered. These individuals are potentially at risk of being parents to off-springs affected by β-thalassemia major, hemoglobin (Hb) H disease, and Hb Bart's hydrops fetalis. We propose screening for the (-(SEA)) α-thalassemia mutation in all β-thalassemia carriers to prevent hydrops fetalis.link_to_subscribed_fulltex