However, the prime targets of thalassemia screening in the region are β- and α0-thalassemia carriers and Hb E since the three thalassemic diseases to be prevented are β-thalassemia major, Hb E-β-thalassemia and Hb Bart’s hydrops fetalis caused by homozygous α0-thalassemia. This evidence concerns the gene GSTM1 and hydrops fetalis.