GSTM1 and thalassemia: Compared to the normal group, the levels of erythrocyte system indicators, including hemoglobin (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC), decreased in all three α-thalassemia groups, with the most significant decrease observed in the Hb H group (P <  0.001), falling below clinical normal reference ranges.