WIDE SPECTRUM OF MUTATIONS IN THE BETA-GLOBIN GENE CAUSING BETA-THALASSEMIA MAJOR IN SOUTHWEST IRAN

Background and Aim: Beta-thalassemia (b-thalassemia) is characterized by the reduced synthesis of the hemoglobin beta chain. Nowadays, more than 200 disease-causing mutations in beta-globin (b -globin) gene have been identified. Beta-thalassemia is the most common monogenic disease worldwide and one of the widespread hereditary disorders in Iran. Considering the vast spectrum of beta-thalassemia mutations, it has multi-ethnic population. The gene frequency of betathalassemia is high and varies considerably in each region. Therefore, it is necessary to determine the frequency and distribution of beta-thalassemia mutations in different regions.Materials and Methods: In the present study, two hundred and two beta-thalassemia major patients were subjected for genomic DNA extraction from whole blood. Amplification and subsequent sequencing of the beta-globin gene has been made by specific primers.Results: Thirty mutations were found in 404 studied alleles. Our results show that IVSII-1(G A) with 21.3% (86.404 alleles) represents the most common mutation, followed by the four mutations namely CD36.37 (-T) (16%), IVSI-110(G A) (17.8%), IVSI-5(G C) (6.9 %) and CD5 (-CT) (5.2%), respectively.Conclusion: Our findings indicate that the Khuzestan population possesses a wide variety of thalassemia allelic distribution. These results can be used as basis for prenatal diagnosis of beta-thalassemia, especially in the south west of Iran