The Spectrum of β-Thalassemia Mutations in Batman, South-Eastern Turkey

Abstract

Objective: In this study, we aimed to determine the mutation types and the frequencies of these mutations in the patients with thalassemia in Batman province and to provide the use of these findings in genetic counselling.
 Methods: The study included 46 patients (27 male and 19 female) with a mean age of 9.5 ± 3.6 years (range: 3-16 years). In this study, mutations were determined by sequence analysis method.
 Results: 7 different mutations were detected in patients. IVS-I-110 (G>A) (56.25%), codon 44 (-C) del (16.25%), IVS-I-1 (G>A) (12.5%), IVS- II-1 (G>A) (6.25%) were the most common and they were found to constitute 91.25% of the cases. As in other regions of Turkey, IVI-1-110 (G >A) was the most frequent mutation detected. In this study; 28 mutant alleles including IVS-I-110 (G>A)/IVS-I-1 (G> A) (4), IVS-I-110 (G>A)/IVS-II-1 (G> A) (4), codon 8 (-AA) del/IVS-1-110 (G>A) (1), codon 8 (-AA) del/ codon 44 (-C)del (1), codon 15 (GG-GA)/codon 44 (-C) del (1), codon 44 (-C) del/IVS-I-1 (G> A) (1), codon 44 (-C) del/ IVS-II-1 (G> A) (1), codon 44 (-C)del/IVS-I-110 (G>A) (1) were found to have formed a compound heterozygous mutation. Among the β-thalassemia patients in Batman province, 29 (56.25%) were determined to have β⁺ mutation, and 26 (43.75%) had β° mutation.
 Conclusion: It is important that we, in our study, discovered IVS-II-1 (G>A) mutation compounded with heterozygous in five patients and codon 8 (-AA) del mutation as homozygous in one patient who presented a clinical manifestation of thalassemia intermedia despite having homozygous beta thalassemia. These results will contribute to genetic counseling and prenatal diagnosis.