Beta-Thalassemia Mutations in the East of Turkey

Abstract

This study was planned to determine the frequency of β-thalassemia trait and mutations in Van Lake region, which is in the eastern part of Turkey, surrounded by Iran in the east and by Iraq in the south. This study consist of 1014 healthy students, between the age of 12 and 18 years who are studying in boarding schools in Van city and cities surrounding Van Lake that includes Van, Aǧri, Hakkari, Bitlis, Muş and Siirt. The students were randomly selected according to their school numbers. Their origin was not taken into consideration in selection. Complete blood counts were performed on all donors. The accepted lower limit of mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were 78 fL and 27 pg respectively. HbA2 was measured by DE-52 microcolumn chromatography method. β-Thalassemia trait with high HbA2 was found in 6 children. β-Thalassemia homozygous form of -30 (T-A) mutation was determined in one child and HbD-Los Angeles heterozygous in another. The β-thalassemia homozygous individual was accepted as two cases in prevalence calculation. We found that the prevalence of β-thalassemia trait was 0.78% in this area. In DNA analyses, there were β-thalassemia gene mutations of FSC 8/9 (+G), -30 (T-A), IVS I-110 (G-A), IVS II-1 (G-A) and IVS I-130 (G-A) in 3, 2, 1, 1 and 1 individuals, respectively. We conclude that although five different β-thalassemia mutation exist in Van Lake region, β-thalassemia is not a potential risk in the east of Turkey.