| Groups | n | Genotype frequencies (%) | Allele frequency (%) | |||
| LL | SL | SS | L | S | ||
| The Study Group (PTSD) | 57 | 5 (8.8) | 16 (28.1) | 36 (63.1) | 26 (22.8) | 88 (77.2) |
| The control group | 57 | 16 (28.1) | 22 (38.6) | 19 (33.3) | 54 (47.4) | 60 (52.6) |
| χ2 |
| 11.96 | 15.10 | |||
| P |
| 0.003 | 0.000 | |||