A1555G Polymorphism and Aminoglycoside‐induced Hearing Loss from Intratympanic Gentamicin Therapy

Abstract

Objectives: Intratympanic gentamicin (ITG) treatment has become a standard modality in treating patients with Ménière’s disease (MD) with high success rate. However, 30% of the ITG patients may suffer from further hearing recession. The relation of a genetic variation in the mitochondrial rRNA gene, A1555G, and aminoglycoside-induced hearing loss (AIHL) remains unknown. The aim of the present study was to evaluate whether the presence of A1555G polymorphism in the mitochondrial rRNA gene can predispose to the AIHL in MD patients following ITG. Methods: 33 Ménière’s disease patients received ITG therapy. Genomic DNA was extracted from their blood samples. Target fragment within mitochondrial rRNA gene was amplified by polymerase chain reaction, and genotyped by direct sequencing to search for 1555 A-to-G substitution. Results: 33 patients (13 males and 20 females; mean age: 56.2 years old) met the inclusion criteria. None of the subjects demonstrated this specific A-to-G substitution. Whether the patients will suffer from AIHL is independent of the presence of A1555G polymorphism. Conclusions: ITG treatment for intractable Ménière’s disease appears to be effective in the relief of vertigo. However, we disagree with the relationship between A1555G polymorphism and antibiotic-induced ototoxicity reported by Prezant et al. There might be different significant single nucleotide polymorphisms that may predispose to the hearing loss following ITG treatment. Further genotypes involving in this treatment must be analyzed in various populations.