Glutathione S-transferase gene polymorphisms in Italian patients with sudden sensorineural hearing loss

HYPOTHESIS: To investigate the association between glutathione S-transferase (GST) gene polymorphisms and sudden sensorineural hearing loss (SSNHL) in a population of consecutive Italian patients. Assuming that reactive oxygen species formation may play a role in inner ear damage, we investigated whether profiles of GSTs antioxidant enzymes M1 and T1 genotypes may be associated with the risk of SSNHL. STUDY DESIGN: A prospective study in patients with SSNHL. PATIENTS AND METHODS: We investigated 80 Italian patients with SSNHL for the frequency of GSTT1 and GSTM1 polymorphisms. Genotype distribution of all factors found in patients were compared with those of 80 healthy control subjects of the same ethnic background using χ and odds-ratio analysis. Statistical significance was accepted at a level of p <0.05. RESULTS: In our series, the frequencies of GSTM1 and GSTT1 null genotypes did not differ from those of the control subjects. CONCLUSION: The few studies regarding genetic polymorphisms of GSTs in SSNHL are not conclusive. Further studies are needed to investigate the role of antioxidants including GSTs in SSNHL and to provide the lacking information to improve our knowledge in the field before implementing the use of genetic polymorphism in the SSNHL medicine daily practice.