Beta-globin gene mutations in children with beta-thalassemia major from Şanlıurfa province, Turkey.
OBJECTIVE
The prevalence of β-thalassemia in Şanlıurfa province, Turkey is reported to be 2.6%-3.7%, whereas nation-wide the frequency of β-thalassemia is 2%. This study aimed to identify the most frequent β-thalassemia mutations in Şanlıurfa province.


METHODS
In total, 22 mutations were investigated in 115 pediatric patients with β-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 β-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 Şanlıurfa 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), IVS-1-110 (G>A)/codon 39 (C>T) (n=1), IVS-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>A]/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 β-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.


CONCLUSIONS
The present results illustrate the heterogeneity of β-thalassemia mutations in Şanlıurfa Province. The present findings may be of value for genetic counseling, and premarital and prenatal diagnosis in Şanlıurfa province.
Department of Pediatric Hematology, Faculty of Medicine, Harran University, Şanlıurfa, Turkey Phone: +90 414 318 30 00 E-mail: ayciceka@hotmail.com.
Ali
A
Ayçiçek
Ahmet
A
Koç
Zeynep Canan
ZC
Özdemir
Hasan
H
Bilinç
Abdurrahim
A
Koçyiğit
Fuat
F
Dilmeç