Molecular Spectrum of β-Thalassemia Mutations in Northwestern Iran

Abstract

Background and objective: β -Thalassemia is a hereditary autosomal disorder with decreased or absent β -globin chain synthesis. This study was designed to identify the common and rare β -thalassemia mutations in the Azerbaijan provinces, Northwestern Iran, and to set up a prenatal diagnostic laboratory. Materials and Methods: One hundred unrelated patients with known β-thalassemia major and intermedia, registered with the thalassemia clinics in provincial capitals of Tabriz and Ardebil, were examined. Mutations were studied in 200 chromosomes, by Polymerase Chain Reaction-Amplification Refractory Mutation System (PCR-ARMS) and direct Sequencing methods. Results: Seventeen different β- thalassemia mutations were found in this region of Iran. The results showed that IVS-II-1 (GA) mutation was the most frequent, comprising 21% of all mutations. Other common mutations were IVS-I-110 (GA) 18%, FSC-8/9 (+G) 14.5%, FSC-8 (-AA) 8% and IVS-I-1 (GA) 7.5%. The other mutations were as follows; IVS-I-5 (GC), FSC-44 (-C), Cd15 (TGGTGA), FSC-5 (-CT), IVS-I-6 (TC), IVS-II-848 (CA), FSC-36/37 (-T), -28 (AC), FSC-25/26 (+T), IVS-II-745 (CG), FSC-16 (-C) and IVS-I-25 (-25bp del). Overall these comprise 95% of β-thalassemia mutations in this region and 5% of the mutations still await exploration. Conclusion: The results of this study showed the similarities and differences between this region with the other regions of Iran and neighboring country. This is the first comprehensive study in this region and could be useful for developing β-thalassemia molecular screening plan in Azerbaijan-Iran.