The reduction of α-globin chains in α-thalassaemia is most frequently caused by large deletions (-α3.7, -α4.2, --SEA and --THAI), although non-deletional α-thalassaemia such as Hb Constant spring (αCS) and Hb Pakse (αPS) can occur1, 6–9. This evidence concerns the gene GSTM1 and thalassemia.