β-Globin Gene Mutations in Pediatric Patients with β-Thalassemia in the Region of Çukurova, Turkey

Abstract

β-Thalassemia (β-thal) is one of the most common genetic disorders in Turkey. In this study, we investigated the mutations and frequency of β-thal at the molecular level in pediatric β-thal patients in the Çukurova region. The β-thal mutations of 52 cases were analyzed. An automated blood cell counter was used for hematological data. Cellulose acetate electrophoresis and high performance liquid chromatography (HPLC) methods were used for hemoglobin (Hb) typing. Amplification refractory mutation system (ARMS), restriction fragment length polymorphism (RFLP), gap-polymerase chain reaction (gap-PCR) and DNA sequencing analysis methods were used to determine genomic features. In this study, we found that 36 subjects carried homozygous mutations [IVS-I-110 (G>A) (HBB: c.93-21G>A) (58.3%), codon 8 (–AA) (HBB: c.25_26delAA) (5.6%), −30 (T>A) (HBB: c.-80T>A) (5.6%), IVS-I-6 (T>C) (HBB: c.92+6T>C) (5.6%) and IVS-II-1 (G>A) (HBB: c.315+1G>A) (5.6%)]. We found that 13 subjects carried compound heterozygosities for IVS-I-110/IVS-I-6 (15.4%) and IVS-I-110/frameshift codon (FSC) 44 (–C) (HBB: c.135delC) (15.4%). We observed that the Syrian subject also carried a compound heterozygosity for IVS-I-6/IVS-I-25 (–25 bp) (HBB: c.93_21del). We determined that the most frequently observed β-thal mutation in the Çukurova region, where various types of hemoglobinopathies have been observed, is the IVS-I-110 mutation. As the prevalence of the disease will affect the region where the immigrant population is dense, population screening and prenatal diagnosis (PND) should be increased and the public should be made aware of the consequences.

Keywords:

• β-Thalassemia (β-thal)
• DNA sequencing
• mutation analysis
• prenatal diagnosis (PND)

Acknowledgments

In this study, Dr. F. Guzelgul, Dr. G.S. Seydel, Professor Dr. K. Aksoy (Department of Biochemistry, Faculty of Pharmacy, Tokat Gaziosmanpasa University, Tokat; Zubeyde Hanim Vocational School of Health Services, Nigde Omer Halisdemir University, Nigde and Department of Medical Biochemistry, Faculty of Medicine, Çukurova University, Adana, Turkey) were involved in carrying out the experiments and in writing this article. This research was presented as a poster presentation at the Turkish National Hematology Congress, Titanic Deluxe Belek Hotel, Antalya, Turkey, 21–24 October 2015.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This study was funded from studies titled ‘Establishing the infrastructure of the new methods to be used in the diagnosis of hemoglobinopathies: microarray and bioinformatics’ Project no: 2005K120320-E by The State Planning Organization (SPO), Ankara, Turkey and ‘Determination of proteomic and genomic features for hemoglobinopathies’ Project no: FBE2014D1 by the Çukurova University Research Fund, Adana, Turkey.