Molecular Characterization of β-Thalassemia Mutations Via the Amplification Refractory Mutation System-Polymerase Chain Reaction Method at the North Waziristan Agency, Pakistan

Abstract

β-Thalassemia (β-thal) is a monogenic disease characterized by mutations on the HBB gene, affecting the production of globin that results in hypochromic and microcytic anemia. The aim of this study was to determine the prevalence of six common β-thal mutations, and their frequency and inheritance pattern in affected populations of North Waziristan Agency, Pakistan. In this study, 130 blood samples from 37 unrelated β-thalassemic families having a minimum of one transfusion-dependent child with β-thal major (β-TM), were retrieved either from the Thalassaemia Centre for Women and Children Hospital Bannu or their home towns situated in Noth Waziristan Agency. All samples were analyzed by the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) using six allele-specific primers for the presence of the six β-thal mutations common in the Pakistani population. Of the six common mutations, our study demonstrated five HBB mutations comprising HBB: c.27_28insG, HBB: c.92+5G>C, HBB: c.126_129delCTTT, HBB: c.92+1G>T and HBB: c.17_18delCT from the families studied, while mutation HBB: c.47G>A [codon 15 (G>A)] was not detected in any of the studied families. Furthermore, the HBB: c.27_28insG and HBB: c.92+5G>C were noted to be the most common with frequencies of 42.85 and 31.42%, respectively. The findings of the present study may be useful in launching carrier screening and prenatal diagnosis (PND) programs by screening analyzed and other unanalyzed affected families for the possible presence of common mutations through the ARMS-PCR technique that will help to control the disease.