The role of mitochondrial tRNAPhe C628T variant in deafness expression.

Mutations in mitochondrial genome are one of the most important causes of hearing loss, of these, mitochondrial tRNA (mt-tRNA) genes are the hot spots for mutations associated with deafness. Most recently, a novel mt-tRNA(Phe) C628T variant has been reported to be associated with non-syndromic and sensorineural hearing loss. To test this association, we characterized the C628T variant using a phylogenetic approach; in addition, we employed the bioinformatics tool to predict the thermodynamic change of the mt-tRNA(Phe) gene with and without this variant. Intriguingly, the C628T variant was not evolutionary conserved and had little effect on mt-tRNA(Phe) folding. Moreover, through the application of the pathogenicity scoring system, we classified the C628T variant as a "neutral polymorphism", suggesting that this variant currently lacked sufficient evident to support as a "pathogenic" mutation.