Investigation of bdnf antisense rna polymophisms in connection with bdnf (brain generated neurotrophic factor) val66met polymophism in chronic tinitus

Tinnitus is the perception of sound in one's ear or in any part of the head without any external warning. Brain-derived neurotrophic factor (BDNF), one of the important factors in neural plasticity, is one of the neurotrophic factors that play a key role in the development of the auditory pathway. The BDNF gene is regulated by a long non-coding BDNF antisense RNA gene (BDNF-AS) located downstream of the gene. Therefore, both BDNF and BDNF-AS may be candidate gene loci that may be effective in hearing. While the relationship between tinnitus and BDNF Val66Met polymorphism has been shown in the literature, there is no study questioning the relationship between BDNF Val66Met polymorphism and BDNF-AS polymorphisms. Therefore, in this study, it was aimed to examine the role of BDNF Val66Met polymorphism and BDNF-AS polymorphisms showing linkage disequilibrium in the pathophysiology of tinnitus. In this study, 85 patients with tinnitus complaints for at least 3 months and 60 patients with tinnitus symptom and no systemic disease who applied to the ENT polyclinic of Aydın Adnan Menderes University Faculty of Medicine were included, and 2cc of peripheral blood was obtained from the patients. A total of 6 BDNF-AS polymorphisms (rs925946, rs10501087, rs1488830, rs4074134, rs1519480, rs10767658) were analyzed from the peripheral blood taken by the Fluidigm SNPType method. When the genotype distribution of BDNF-AS rs925946, rs10767658, rs1519480 polymorphisms was compared with tinnitus patients and control group, statistically significant differences were found (p=0.020, p=0.002, p=0.002, respectively). When the allele frequencies for the rs1519480 polymorphism were compared, a statistically significant xvi difference was found (p=0.009). When rs925946, rs10767658, rs1519480 and rs1488830 polymorphisms were compared with tinnitus duration, a statistically significant difference was found (p=0.029, p=0.029, p=0.041 and p=0.036). In conclusion, BDNF-AS rs925946, rs10767658, rs1519480 and rs1488830 polymorphisms may affect the auditory pathway and may be candidate gene loci for gene polymorphisms that may have an impact on auditory performance in humans. Keywords: BDNF gene, BDNF-AS gene polymorphisms, Chronic tinnitus, Val66Met polymorphism.