| Genotype | Inattentive type n (%) | Restrictive type n (%) | Combined type n (%) | Control | p-value |
| GG | 15 (30%) | 12 (24%) | 23 (23%) | 22 (22.2%) | 0.812 |
| GA | 22 (44%) | 26 (52%) | 57 (57%) | 51 (51.5%) | |
| AA | 13 (26%) | 12 (24%) | 20 (20%) | 26 (26.3%) | |
| Total | 50 | 50 | 100 | 99 |