Identification of a Novel Frameshift Mutation [Codon 3 (+T)] in a Turkish Patient with \beta-Thalassemia Intermedia

Abstract

diseases in the world, is an autosomal recessive disease generally caused by point mutations in the β-globin gene that is located as a cluster on the short arm of chromosome 11 (1-3). Modern molecular techniques have provided a wealth of information about the nature of mutations and their distributions within the world population. More than 200 different mutations affecting diverse levels of β-globin gene expression have so far been identified (2,4,5). These mutations such as frameshifts of the insertion/deletion type and/or nucleotide substitutions have been reported to interfere with the transcription of the β-globin gene, splicing procedures and translation of β-globin mRNA (1-5). All these mutations result in either an absence or reduction of synthesis of β-globin chains (3,6). Insertion or deletion of one or more nucleotides in the coding region of the βglobin gene disrupts the normal reading frame and causes the frameshift. As a result of frameshift the β-globin chain is synthesized as either elongated or truncated (7, 8).