GSTM1 and thalassemia: It showed that α-thalassaemia carriers have higher Hb level (α-thalassaemia carrier: 12.1 ± 1.31; β-thalassaemia carrier: 10.6 ± 1.8, p-value: 0.00 *), MCV (α-thalassaemia carrier: 71.0 ± 6.1; β-thalassaemia carrier: 68.7 ± 7.2, p-value: 0.044 *), MCH (α-thalassaemia carrier: 22.8 ± 2.3; β-thalassaemia carrier: 21.8 ± 2.7, p-value: 0.056) RBC level (α-thalassaemia carrier: 5.3 ± 0.7; β-thalassaemia carrier: 4.9 ± 0.9, p-value: 0.001 *), compared to β-thalassaemia carriers [31].