GSTM1 and thalassemia: In Malaysia, non-deletional α-thalassemia, such as Cd 142 (TAA > CAA) Hb Constant Spring (Hb CS) (HBA2:c.427T > C) and Cd 59 (GGC > GAC) Hb Adana (HBA2:c.179G > A), is notably prevalent [8,9].