GSTM1 and thalassemia: The type of identified thalassemia carriers in both groups consisted of β-thalassemia carrier, β-thalassemia HbE, suspected α-thalassemia, and β-thalassemia Hb variant (53 (83%) vs. 5 (31%); 8 (13%) vs. 2 (13%); 2 (3%) vs. 9 (56%); 1 (1%) vs. 0 (0%), respectively).