title: Association of oxidative stress gene polymorphisms with presbycusis.
abstract: BACKGROUND
  Presbycusis is characterised by etiopathological changes in the cochlea of the inner ear due to genetic and environmental factors and has a serious impact on quality of life. The present study was aimed to evaluate the role of oxidant stress gene polymorphisms in the development of presbycusis.
  
  
  METHODS
  220 subjects with confirmed presbycusis from ENT specialists of MAA ENT hospital, Hyderabad, India from 2012 to 2014 were considered for the study. 270 age and sex matched controls were included in the study. Analysis of gene polymorphisms of SNPs cytochrome P450 1A1 (CYP1A1) 3801 T>C, 2455 A>G and 2453 A>C; glutathione S transferase (GST) T1 and M1; N-acetyl transferase (NAT2) 282 C>T and 857 G>A; uncoupled proteins (UCP1) (-3826) A>G and (UCP2) (866)G>A was carried out. Variations in the allelic and genotypic frequencies obtained were computed and analysed using appropriate statistical methods.
  
  
  RESULTS
  The results of the study indicated that CYP1A1 gene polymorphism at 2453 C>A (adjusted OR: 1.59, 95% CI: 1.01-2.87) and 2455 A>G (adjusted OR: 1.87, 95% CI: 1.07-3.37), double null genotype of GSTM1 and GSTT1 (adjusted OR: 8.88, 95% CI: 4.10-19.19), NAT2 gene at C282T (adjusted OR: 1.77, 95% CI: 1.02-3.11) and G590 A (adjusted OR: 1.83, 95% CI 1.20-3.63) and UCP2 (-866) G>A (adjusted OR: 12.39; 95% CI: 6.51-23.56) showed increased risk for presbycusis while CYP1A1 at 3801 T>C and UCP1 (-3286) A>G exhibited no association. The haplotype combinations of T-G-A of CYP1A1 at 3801, 2455 and 2453 positions as well as T-A of NAT2*6 at 282 and 590 positions were found to contribute significant risk for the onset of presbycusis.
  
  
  CONCLUSIONS
  Gene polymorphisms of CYP1A1 (A2455G, C2453A), NAT2*6 (C282T, G590 A), GST T1/M1 (double null genotype) and UCP2 (G-866 A) were found to contribute significant risk to presbycusis.
authors: MAA Research Foundation, Somajiguda, Hyderabad, Telangana State, India; Institute of Genetics and Hospital for Genetic Diseases, Osmania University, Hyderabad, Telangana State, India.
authors: Santoshi Kumari
authors: SK
authors: Manche
authors: MAA Research Foundation, Somajiguda, Hyderabad, Telangana State, India; Institute of Genetics and Hospital for Genetic Diseases, Osmania University, Hyderabad, Telangana State, India.
authors: Madhavi
authors: M
authors: Jangala
authors: MAA Research Foundation, Somajiguda, Hyderabad, Telangana State, India.
authors: Padmavathi
authors: P
authors: Putta
authors: MAA Research Foundation, Somajiguda, Hyderabad, Telangana State, India.
authors: Raja Meganadh
authors: RM
authors: Koralla
authors: Institute of Genetics and Hospital for Genetic Diseases, Osmania University, Hyderabad, Telangana State, India. Electronic address: jyothycell@rediffmail.com.
authors: Jyothy
authors: J
authors: Akka
mesh_terms: D000328:Adult; D001191:Arylamine N-Acetyltransferase / Q000235:genetics; D016022:Case-Control Studies; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics*; D005260:Female; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D020641:Polymorphism, Single Nucleotide; D011304:Presbycusis / Q000235:genetics*; D011401:Promoter Regions, Genetic; D000071246:Uncoupling Protein 2 / Q000235:genetics*
chemical_list: D001191:Arylamine N-Acetyltransferase; D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase; D000071246:Uncoupling Protein 2; C000604389:UCP2 protein, human; C569463:CYP1A1 protein, human; C478900:NAT2 protein, human; C413545:glutathione S-transferase T1
keywords: Cytochrome P450; Glutathione S transferase; N-acetyl transferase; Presbycusis; Uncoupled proteins