Increased Percentage of β-Thalassemia Carriers in the Region of South-East Rodopi and Kardzali Near Greece and the Mediterranean

Violeta Yordanova,Todor Tcherkezov

doi:10.11648/j.ijcts.20210703.12

Abstract

Objectives: In a brief summary we present the basic aspects of the of the hemoglobinopathies in the population of the South-East Rodopi within the Bulgarian territory and we report the preliminary results for the identification of β-thalassemia carriers by measuring the expression of the HbA fractions. Design and methods: Separation and measurement of the Hb fractions in blood samples collected among the multi-ethnic Bulgarian population using different methods. Results: By using a cut of 3.2% HbA2 we have found 9.77% carriers of point mutations defects among a group of 532 patients of different ethnic origin. All patients’ carriers have also increased HbF. Most frequent point mutation is IVS I nt 110 (G>A). Discussion: All methods summarized in this paper provide identification at practically high sensitivity and specificity. However, all methods should be followed by routine parent's analysis to confirm the provisional results. Taking into consideration the specific conditions of each patient and the HbA expression, we believe carriers of β-thalassemia can be preselected with a reasonable degree of sensitivity and be confirmed by parent analysis. It is important to consider this uneven distribution of the mutations in the hemoglobin being increased in our region as opposed to the overall carriers in the territory of Bulgaria and Europe.

Highlights

Among the hemoglobinopathies the thalassemia is a specific type in which the circulating hemoglobin HbA fractions are over 96% of the hemoglobin in adults and consist of 2 alfa and 2 beta chains (α2β2); tetrameres. βThalassemias are of a particular interest to us due to the higher frequency in our region
Conditions with a greater syntheses of HbF for a compensation are common as inherited stable conditions of fetal hemoglobin (HPFH) and the homozygous are clinically unaffected, while the heterozygous with the β-thalassemia are very mild [5]
Two patients had a typical percentage of hemoglobin fractions as bands on the gel for Delta-Beta Thalassemia intermedia, presented as 0.3% of the total

Summary

Introduction

Among the hemoglobinopathies the thalassemia is a specific type in which the circulating hemoglobin HbA fractions are over 96% of the hemoglobin in adults and consist of 2 alfa and 2 beta chains (α2β2); tetrameres. βThalassemias are of a particular interest to us due to the higher frequency in our region. Most recently the new approaches and scientific understanding of the regulatory mechanisms of the hemopoesis gives hope for the patients with heavy mutations To this date there are still 10 000 registered homozygous careers in Europe and USA [2]. Very common as β-thalassemia or heterozygous β-thalassemia, there is one single β-thalassemic mutation and a normal β-globin gene on the other chromosome. Most patients with the thalassemia intermedia are homozygous or a combination of heterozygous for βthalassemia, as with both β-globin loci affected. Conditions with a greater syntheses of HbF for a compensation are common as inherited stable conditions of fetal hemoglobin (HPFH) and the homozygous are clinically unaffected, while the heterozygous with the β-thalassemia are very mild [5]. For the PCR reaction we used AB StepOne rtPCR system

Patients

Materials and Methods

Conclusion

Discussion