COMMON ΒETA-THALASSEMIA MUTATIONS IN NORTH-WEST OF IRAN

Βeta-thalassemia was first explained by Thomas Cooley as Cooley’s anemia in 1925. β-thalassemias are hereditary autosomal disorders with decreased or absent β-globin chain synthesis. The most common genetic defects in β-thalassemias are caused by point mutations, microdeletions, or insertions within the β-globin gene. In this study, 142 blood samples (64 from the Children’s Hospital of Tabriz, 15 from Shaheed Gazi Hospital of Tabriz, 18 from Urumia, and 45 from Ali-Asghar Hospital of Ardabil) were taken from thalassemic patients (previously diagnosed thalassemia). Afterwards, 117 nonfamilial samples were selected. DNA of the lymphocytes of blood samples were extracted by boiling and the proteinase K-SDS procedure, and mutations were detected using ARMS-PCR methods. From the results obtained, the eleven most common mutations, most of which were Mediterranean mutations, were detected as follows: IVS-I-110(G-A), IVS-I- 1(G-A), IVS-I-5(G-C), frameshift codon 44 (- C), codon5( -CT), IVS-I-6(T -C), IVS-I-25( -25bp del), frameshift 8.9 (+G), IVS-II-1 (G-A), codon 39(C- T), and codon 30(G-C). The mutations of the samples were defined. The results showed that frameshift 8.9 (+G), IVS-I-110 (G-A), IVS-II-I(G-A), IVS-I-5(G-C), IVS-I-1(G-A), frameshift codon 44( -C), codon 5(-CT), IVS-I-6(T-C), and IVS-I-25(-25bp del) with frequencies of 29.9%, 25.47%,17.83%, 7.00%, 6.36%, 6.63%, 3.8% , 2.5% , and 0.63%, respectively represented the most common mutations in North-West of Iran. No mutations in codon 39(C-T) or codon 30(G-C) were detected. The frequency of the same mutations in patients from North-West of Iran seems to be different as compared with other regions such as Turkey, Pakistan, Lebanon, and the Fars Province of Iran. The pattern of mutations in this region is more-or-less the same as in the Mediterranean region, but different from South- West and East Asia.