title: Glutathione S-transferase gene polymorphisms in presbycusis.
abstract: OBJECTIVE
  Glutathione and glutathione-related antioxidant enzymes are involved in the metabolism and detoxification of cytotoxic and carcinogenic compounds as well as reactive oxygen species. Reactive oxygen species generation occurs in prolonged relative hypoperfusion conditions such as in aging. The etiology of presbycusis is much less certain; however, a complex genetic cause is most likely. The effect of aging shows a wide interindividual range; we aimed to investigate whether profiles of (glutathione S-transferase (GST) M1, T1 and P1 genotypes may be associated with the risk of age-related hearing loss.
  
  
  METHODS
  We examined 68 adults with presbycusis and 69 healthy controls. DNA was extracted from whole blood, and the GSTM1, GSTT1 and GSTP1 polymorphisms were determined using a real-time polymerase chain reaction and fluorescence resonance energy transfer with a Light-Cycler Instrument. Associations between specific genotypes and the development of presbycusis were examined by use of logistic regression analyses to calculate odds ratios and 95% confidence intervals.
  
  
  RESULTS
  Gene polymorphisms at GSTM1, GSTT1, and GSTP1 in subjects with presbycusis were not significantly different than in the controls (p > 0.05). Also, the combinations of different GSTM1, GSTT1, and GSTP1 genotypes were not an increased risk of presbycusis (p > 0.05).
  
  
  CONCLUSIONS
  We could not demonstrate any significant association between the GSTM1, GSTT1, and GSTP1 polymorphism and age-related hearing loss in this population. This may be because of our sample size, and further studies need to investigate the exact role of GST gene polymorphisms in the etiopathogenesis of the presbycusis.
authors.affiliation: Department of Medical Biology and Genetics, Mersin University School of Medicine, Mersin, Turkey.
authors.forename: Nurcan Aras
authors.initials: NA
authors.lastname: Ateş
authors.forename: Murat
authors.initials: M
authors.lastname: Unal
authors.forename: Lülüfer
authors.initials: L
authors.lastname: Tamer
authors.forename: Ebru
authors.initials: E
authors.lastname: Derici
authors.forename: Sevim
authors.initials: S
authors.lastname: Karakaş
authors.forename: Bahadir
authors.initials: B
authors.lastname: Ercan
authors.forename: Yavuz Selim
authors.initials: YS
authors.lastname: Pata
authors.forename: Yücel
authors.initials: Y
authors.lastname: Akbaş
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Vayisoğlu
authors.forename: Handan
authors.initials: H
authors.lastname: Camdeviren
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase / Q000235:genetics*; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011304:Presbycusis / Q000235:genetics*
chemical_list: D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase; D007527:Isoenzymes; C413545:glutathione S-transferase T1; C496556:GSTP1 protein, human