GSTM1 and beta thalassemia: A total of 43 diabetic patients were identified to have hemoglobin variants: elevated Hb F (13×), heterozygous Hb E (12×), heterozygous Hb S (7×), homozygous Hb S (1×), heterozygous Hb D (7×), Hb E / beta-Thalassemia (2×), and heterozygous Hb C (1×).