role of xmnigg polymorphism in hydroxyurea treatment and fetal hemoglobin level at isfahanian intermediate β-thalassemia patients

background: &beta-thalassemia; is the most common monogenic disorder in human. the (ct) polymorphism at -158 upstream region of the &gammag-globin; gene and pharmacological factors such as hydroxyurea have been reported to influence &gamma-globin; gene expression and the severity of clinical symptoms of &beta-thalassemia.; methods: in the present study, 51 &beta-thalassemia; intermediate patients were studied. xmn1&gammag; polymorphism genotype was determined using tetra-primer arms-pcr technique. hemoglobin (hb) and fetal hemoglobin (hbf) levels were determined by gel electrophoresis. results: of 51 patients, 35 (68.6%) patients were heterozygous (ct) and 16 (31.4%) patients were homozygous (cc). of 30 patients under treatment by hydroxyurea, 20 (66.7%) patients were heterozygous (ct) and 10 (33.3%) patients were homozygous (cc). our results demonstrated that in the heterozygous (ct) genotype, the hb (9.58 ± 1.25 gm/dl) and hbf (89.30 ± 21.87) levels were significantly higher in comparison with homozygous (cc) genotype (7.94 ± 1.34 gm/dl and 70.32 ± 40.56, respectively). furthermore, we observed that after drug usage, the hb and hbf levels in patients with heterozygous (ct) genotype (0.7 ± 1.26 gm/dl and 5.95±14.8, respectively) raised more in comparison with homozygous (cc) genotype (0.26 ± 1.43 gm/dl and 0.8±1.31, respectively). conclusion: hb and hbf levels in the patients carrying t allele are increased significantly, and they also response to hydroxyurea treatment.