Approximately one-third of the children (39.3 %) had no evidence of a clinically significant IHbD, 2.8 % had α0-thalassaemia trait, 42.7 % had Hb E trait, 13.4 % had β-thalassaemia trait or were homozygous for Hb E and 1 .8 % had α- or β-thalassaemia disease (Table 1). Here, GSTM1 is linked to thalassemia.