Evaluation of the High Resolution Melting Approach for Detection of β-Thalassemia Gene Mutations

Abstract

β-Thalassemia (β-thal), an autosomal recessive hemoglobinopathy, is one of the most common genetic disorders in Pakistan. Awareness of this disease, genetic counseling, extended family carrier screening and prenatal diagnosis (PND) are helpful in prevention and control. Currently, direct DNA sequencing and multiple amplification refractory mutation system-polymerase chain reaction (MARMS-PCR) are the methods used to detect β-thal mutations, the latter being the most widely used. This study aimed to evaluate PCR-high resolution melting (PCR-HRM) analysis for the detection of most common β-thal mutations that are found in Pakistan. This study was designed to identify the β-thal mutations using PCR-HRM analysis in a total of 90 samples [blood and chorionic villus sampling (CVS)]. These samples were first screened for routine mutations by MARMS-PCR and then evaluated by PCR-HRM analysis. The results of PCR-HRM analyses were further confirmed by direct DNA sequencing and all analyses interpreted the same results in all 90 samples. Eleven cases (36.6%) were detected to carry IVS-I-5 (G>C) (HBB: c0.92 + 5G>C), six cases (20.0%) with frameshift codons (FSC) 41/42 (–TTCT) (HBB: c.126_129delCTTT), five cases (16.0%) were diagnosed with codon 15 (G>A) (HBB: c.47G>A), three cases (10.0%) were found with codon 30 (G>C) (HBB: c.93G>C), one case was diagnosed with FSC 16 (–C) (HBB: c.51delC), one with IVS-I-1 (G>T) (HBB: c0.92 + 1G>T) and one with codon 5 (–CT) (HBB: c.17_18delCT). The PCR-HRM analysis represents a less tedious and more useful method for the detection of β-globin gene mutations.