Beta-globin gene mutations in children with beta-thalassemia major from Sanliurfa province, Turkey

Objective: The prevalence of (beta-thalassemia in Sanhurfa province, Turkey is reported to be 2.6%-3.7%, whereas nation-wide the frequency of beta-thalassemia is 2%. This study aimed to identify the most frequent beta-thalassemia mutations in Sanhurfa province. Materials and Methods: In total, 22 mutations were investigated in 115 pediatric patients with beta-thalassemia using a commercially available reverse dot blot platform. Results: The study included 60 male and 55 female patients with a mean age of 7.3 +/- 4.6 years (range: 1-17 years). In total, 76% of the patients had consanguineous parents. In all, 16 different mutations were observed in the 115 patients. IVS-1-110 (G-A) (29.1%), IVS-1-1 (G-A) (13.9%), codon 39 (C>T) (10.4%), and codon 8 (-AA) (9.1%) accounted for 62.5% of all the beta-thalassemia mutations, and 6% of the patients had 2 different thalassemia mutations. According to the present results, IVS-1-110 (G>A) was the most frequent mutation observed in the patients from Sanhurfa province, as in other geographical regions of Turkey. In addition, the following 34 compound heterozygote mutant alleles were observed; IVS-1-1 (G>A)/IVS 2.848 (n=4), codon 39 (C>T)/codon 8 (-AA) (n=2), codon 6 (-A)/IVS 1.5 (G>C) (n=2), IVS-1-110 (G>A)/IVS-1-1 (G>A) (n=2), IVS-1-110 (G>A)/codon 8 (-AA) (n=1), TVS-1-110 (G>A)/codon 39 (C>71) (n=1), NS-1-110 (G>A)/IVS-1-6 (T>C) (n=1), IVS-1-110 (G>A)/IVS-1-5 (G>C) (n=1), IVS-1-110 (G>A1/codon 8/9 (+G) (n=1), IVS-1-1 (G>A)/codon 39 (C>T) (n=1), and codon 8 (-AA)/IVS-1-5 (G>C) (n=1). The following beta-globin gene promoter mutations were not observed; -101 (C>T), -87(C>T), -30 (T>A), codon 15 (TTG>TGA), codon 27 (G>T) Knossos, and IVS-1-116 (G>C). In all, 5 of the 115 patients (4.3%) had an unidentified mutation. Conclusion: The present results illustrate the heterogeneity of beta-thalassemia mutations in Sanhurfa Province. The present findings may be of value for genetic counseling, and premarital and prenatal diagnosis in Sanhurfa province. (Turk J Hematol 2011; 28: 264-8)