The most common nondeletional α-thalassaemia mutations in Southeast Asia are Hb Constant Spring (HbCS) (HBA2:c.427T>C), Hb Adana (HBA2:c.179G>A), Hb Quong Sze (HbQS) (HBA2:c.377T>C), Hb Paksé (HBA2:429A>T) and Hb Suan Dok (HBA2:c.329T>G)7, 8, 9, 10. Here, GSTM1 is linked to thalassemia.