Table 2.
Association between genotype frequency for the TNFA −308 G/A gene polymorphism and tinnitus related to history of occupational noise exposure (n = 179)
| Occupational noise exposure | Genotyping | No tinnitus n (%) | With tinnitus n (%) | P-value and chi-square test |
|---|---|---|---|---|
| No history | Genotypic frequency | |||
| GG | 42 (61.7) | 40 (78.4) | P = 0.02 | |
| AA | 12 (17.6) | 1 (01.9) | χ 2 = 7.75 | |
| GA | 14 (20.7) | 10 (19.7) | ||
| Allelic frequency | ||||
| G | 98 (72.1) | 90 (88.2) | P = 0.00 | |
| A | 38 (07.9) | 12 (11.8) | χ 2 = 9.19 | |
| With history | Genotypic frequency | |||
| GG | 16 (45.7) | 19 (76) | P = 0.04 | |
| AA | 10 (28.5) | 2 (08) | χ 2 = 6.01 | |
| GA | 9 (25.8) | 4 (16) | ||
| Allelic frequency | ||||
| G | 41 (68.3) | 42 (84) | P = 0.09 | |
| A | 19 (31.7) | 8 (16) | χ 2 = 3.61 | |
n = number of participants, % = percentage, GG = mutant homozygotes, AA = wild-type homozygotes, AG = heterozygotes, P = P-value; χ 2 = chi-square test.