The frequency and spectrum of HBB gene mutation in β-Thalassemia patients in Saudi Arabia

Abstract

Background: β-thalassemia is an autosomal disorder of the blood caused by mutations in HBB gene responsible for the production of β-globin. The HBB mutations reduce the synthesis of β-globin which results in severe anemia. A high frequency of β-thalassemia is reported in Saudi Arabia, and hence this study assessed the most frequent β-thalassemia mutations in Saudi Arabia. Materials and Methods: Data of preimplantation genetic diagnosis and gene sequencing for 59 β-thalassemia patients and carriers were collected from the electronic medical record system at KFSH and RC and were analyzed using SPSS version 19. Results: Twelve mutations were confirmed in the five regions investigated in this study. Cd39 was identified as the most frequent mutation with a frequency of 22.7%, with high prevalence in the central parts of Saudi Arabia. IVS-II-1 G > A was the second frequent mutation observed with a frequency of 21.2%, while IVS-I-1 (G-A) and IVS I-130G>C mutations were observed to be least frequent in the study. Of the 12 gene mutations, 85% were frequently observed in Saudi Arabia, while 15% were less frequent. The regional distribution of HBB gene mutations varied considerably. Conclusion: The population diversity in Saudi Arabia contributes to the variability in the prevalence rates of HBB gene mutations. Nevertheless, this study identifies Cd39 and IVS-II-1 G > A as the predominant mutations in HBB gene in Saudi Arabia.