GSTM1 and thalassemia: Thalassemia major includes homozygous β0-thalassemia, some cases of Hb Eβ-thalassemia, and homozygous α0-thalassemia 1 (Hb Bart’s hydrops fetalis syndrome) [4]; the latter being the most severe form from which patients usually die in utero or soon after birth [5].