Molecular characterization of beta-thalassemia reveals the presence of common mutations in the population of Himalayan region: Garhwal (Uttarakhand), India

Thalassemia is a dreadful heritable hemolytic disease, characterized by a genetic mutation in the hemoglobin subunit beta (HBB) gene. Mutation in HBB gene completely halts the production of the beta-globin protein, which leads to the defective production of functional hemoglobin. The prevalence of this disease is reported only in some specific geographical regions of India. Hence, the aim of this study was to screen the population of Garhwal for beta-thalassemia (β-thalassemia) and thus find out the prevalence in the inhabitants through molecular characterization. For this study, 4,081 individuals were considered, out of which only the ones with elevated HbA2 levels (64) were subjected to molecular characterization. Mutational studies were carried out for the five most common mutations prevalent in the Indian subcontinent, that is, IVS 1-5 G-C, IVS 1-1 G-T, Codon 41/42 (-TCTT), Codon 8/9, and 619 bp deletion. The present study reports a frequency of 0.5% for β-thalassemia mutations among the subjects we have studied. The analysis of mutation spectrum revealed highest prevalence for IVS-1-5 (G-C) (18.75%) followed by Codon 8/9 (12.5%) and IVS-1-1 (G-T) with 6.25%. Codon 41/42 (-TCTT) and 619 bp deletion were found to be absent in our study population.