GSTM1 and thalassemia: Additionally, this study found that HbF, HbA, and Hb Barts have the value of diagnosing and differentiating thalassemia, as well as the RBC, MCV, MCH and percentage of NRBCs in β-thalassemia and RBC, Hb, HCT, MCV, MCH, MCHC, RDW in α-thalassemia.