In our study, patients with deletional genotypes of α‐thalassemia were found to have higher RBC and lower Hb, MCV, MCH, and HbA2 than patients with non‐deletional genotypes of α‐thalassemia (p < 0.05).It may be related to the damage of erythrocyte membrane caused by excess β‐chain oxidation and αQSα or αCSα chain oxidation. Here, GSTM1 is linked to thalassemia.