Genetic polymorphism of antioxidant enzymes in patient with thympanosclerosis chronical otitis media

In this study, genetic polymorphism of inducible nitric oxide synthetase (iNOS), superoxide dysmutase (SOD) and catalase enzymes were analyzed in patients with thympanosclerosis (TS) chronical otitis media (COM), therefore role of genetic predisposition in TS etiology was researched.32 persons who did not have any ear problem or known chronical systemic disease, and 64 patients who were operated because of COM were included in this study. Three groups were created: COM with thympanosclerosis, COM without thympanosclerosis and the control group. DNA insulation was performed from venous blood samples taken from the patients and the control group. Genetic polymorphism was evaluated through the examination of reverse transcriptase polymerase chain reaction (RT PCR).GG genotype dispersion was found as 13 (40%), 7 (22%) and 4 (12%) in COM with thympanosclerosis, COM without thympanosclerosis and the control group respectively, for A/G polymorphism in inducible nitric oxide synthetase (NOS2) gene (-277). GG genotype dispersion between COM with thympanosclerosis group and the control group was statistically meaningful (p=.008).CC genotype dispersion was found as 8 (25%), 7 (22%) and 4 (12%) in the group of KOM with thympanosclerosis, COM without thympanosclerosis and the control group respectively, for superoxide dysmutase (mn-SOD) A16V (C/T) polymorphism. Even though CC genotype number increased in the group of COM with thympanosclerosis and thympanosclerosis without COM compared to the control group, no meaningful difference was found statistically.TT genotype dispersion was found as 6 (20%), 2 (6%) and 3 (9%) for COM with thympanosclerosis, COM without thympanosclerosis and the control group respectively, for A/T variation polymorphism in -21 position in catalase gene. Even though TT genotype number increased in the group of COM with thympanosclerosis compared to the control group, no statistical relevance was identified.In this study, it was identified that GG genotype of iNOS (NOS2) gene (-277) was significantly increased in patients with thympanosclerosis COM, compared to the healthy individuals. Consequently; it was concluded that genetic predisposition could play a big role in etiopathogenesis of thympanosclerosis.Keywords: Thympanosclerosis, inducible nitric oxide synthetase, superoxide dysmutase, catalase, genetic polymorphism