Hb H disease is characterized by a significant deficiency of α-globin, leading to the excessive formation of β-globin chains that result in the production of unstable hemoglobin, known as Hb H. This condition can present with varying degrees of anemia, ranging from mild to severe, and exhibits considerable clinical heterogeneity (Lal et al., 2011). This evidence concerns the gene GSTM1 and anemia (phenotype).