Identification of compound heterozygosity for a rare beta-globin gene mutation, codon 15 (-T) with a common mutation IVS1-5 (G>C) by direct sequencing in a Bangladeshi patient

Abstract

Most of the beta-thalassemia cases in Bangladesh are caused by 5-7 common mutations in the beta-globin gene. The present study reports a rare mutation in compound heterozygosity with a common mutation in beta-globin gene of a thalassemic patient first time in Bangladesh. A Bangladeshi individual, born to a family of carrier mother and normal father was diagnosed with abnormal hemoglobin electrophoresis result. Sequencing analysis revealed the presence of a rare mutation caused by the deletion of a thymine at c.46 of b- globing gene, HBB: c.46delT [codon 15 (-T)]. A second common mutation HBB: c.92+5 G>C [IVS1-5 (G>C)] was also identified along with the rare mutation. This compound heterozygous condition produced significant reduction in the synthesis of beta-globin chain. This study recommends the necessity of integrating direct sequencing evaluation during prenatal screening program and antenatal diagnosis of thalassemia cases.