Introduction: Men are more susceptible to impulsive behavior than women. Epidemiological studies revealed that the impulsive aggressive behavior is affected by genetic factors, and the male-specific Y chromosome plays an important role in this behavior. In this study, we investigated the association between the impulsive aggressive behavior and Y-chromosomal short tandem repeats (Y-STRs) loci.
Methods: The collected biologic samples from 271 offenders with impulsive aggressive behavior and 492 healthy individuals without impulsive aggressive behavior were amplified by PowerPlexRY23 PCR System and the resultant products were separated by electrophoresis and further genotyped. Then, comparisons in allele and haplotype frequencies of the selected 22 Y-STRs were made in the two groups.
Results: Our results showed that there were significant differences in allele frequencies at DYS448 and DYS456 between offenders and controls (p < .05). Univariate analysis further revealed significant frequency differences for alleles 18 and 22 at DYS448 (0.18 vs 0.27, compared to the controls, p = .003, OR=0.57,95% CI=0.39-0.82; 0.03 vs 0.01, compared to the controls, p = .003, OR=7.45, 95% CI=1.57-35.35, respectively) and for allele 17 at DYS456 (0.07 vs 0.14, compared to the controls, p = .006, OR=0.48, 95% CI =0.28-0.82) between two groups. Interestingly, the frequency of haploid haplotype 22-15 on the DYS448-DYS456 (DYS448-DYS456-22-15) was significantly higher in offenders than in controls (0.033 vs 0.004, compared to the control, p = .001, OR = 8.42, 95%CI =1.81-39.24). Moreover, there were no significant differences in allele frequencies of other Y-STRs loci between two groups. Furthermore, the unconditional logistic regression analysis confirmed that alleles 18 and 22 at DYS448 and allele 17 at DYS456 are associated with male impulsive aggression. However, the DYS448-DYS456-22-15 is less related to impulsive aggression.
Conclusion: Our results suggest a link between Y-chromosomal allele types and male impulsive aggression.
Keywords: Y chromosome; allele; behavior; genetics; haploid; haplotype; impulsive aggression; male; offender; polymorphisms; short tandem repeats.