Angiotensin-Converting Enzyme (ACE) I/D and Alpha-Adducin (ADD1) G460W Gene Polymorphisms in Turkish Patients with Severe Chronic Tinnitus.

OBJECTIVE Tinnitus is described as a disturbing sound sensation in the absence of external stimulation. We aimed to investigate whether there is any relationship between severe chronic tinnitus and angiotensin-converting enzyme (ACE) I/D and α-adducin (ADD1) G460W gene polymorphisms. MATERIALS AND METHODS The patient group and control group consisted of 89 and 104 individuals, respectively. The evaluation of tinnitus was performed using the Strukturiertes Tinnitus-Interview (STI). The Tinnitus Handicap Inventory (THI) was used to evaluate the tinnitus severity. Polymerase chain reaction (PCR) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques were used for genotyping. RESULTS With regard to the ACE I/D polymorphism, there was no significant difference in genotype and allele frequencies between the patient group and control group. However, a statistically significant difference was found in genotype (p<0.01) and allele frequencies (p=0.021) of the ADD1 G460W gene polymorphism. Combined genotype analysis showed that the ACE II /ADD1 GW genotype was statistically significantly higher in the patient group than in the control group (X2: 7.15, p=0.007). The odds ratio value of the GW genotype was 2.5 (95% CI=1.4-4.7) (p<0.01). CONCLUSION Our results demonstrate an association between ADD1 G460W gene polymorphism and susceptibility to severe chronic tinnitus. It was found that the GW genotype increased the disease risk by 2.5-fold compared with other genotypes. This indicates that ADD1 G460W polymorphism could be an important factor in the pathophysiology of tinnitus.