Abstract

Noise exposure leads to hearing loss in industrial workers due to release of superoxide anions which damage cochlear epithelium in the ear. These free radicals are regulated by superoxide dismutase 2 (SOD2) and polymorphism in this gene may abet in predisposition to noise induced hearing loss (NIHL). The current study describes prevalence of polymorphism at two different loci of SOD2 gene in NIHL patients and association of smoking habit with NIHL. PCR-SSCP analysis of polymorphic sites revealed mutation in NIHL patients. Results showed thatIVS1+8A/G and IVS3-23T/G SOD2 polymorphisms are associated with NIHL (p< 0.05, CI 95%) irrespective of smoking habit (p > 0.01). It is intended that SOD2 polymorphism plays a significant diagnostic role in determining susceptibility of NIHL in Pakistani industry employees.

Key words: Superoxide dismutase 2, polymorphism, hearing loss, loci, reactive oxygen species