The mean Hb of heterozygotes β°-thal SEA deletion (13.44 ± 1.45 g/dl) was significantly higher than heterozygotes β°-thalassemia mutations of IVS 1-1 (G > T) (β°) (HBB:c.92 + 1G > T) and Codon 41/42 (-TTCT) (β°) (HBB:c.126_129delCTTT) (post hoc test, p < 0.05). The gene discussed is GSTM1; the disease is thalassemia.