GSTM1 and alpha thalassemia spectrum: Regarding the comparison of red blood cell indices between the normal group and the α+-thalassemia trait group, the levels of Hb, MCV, MCH, and MCHC were significantly lower in the α+-thalassemia trait group, whereas the RDW and RBC count were significantly higher in the α+-thalassemia trait group, as presented in Table 2.