• forensic science;
  • catechol O-methyl transferase;
  • DNA polymorphism;
  • polymerase chain reaction;
  • committed;
  • mental retardation

Abstract:  Little is known about criminality of cognitively impaired people and also there have been no reports on the relationship between catechol-O-methyl transferase (COMT) and committed Mental Retardation (MR) subjects. In the present study, the association between committed (violent offences) MR subjects and genetic variants of COMT were investigated by using polymerase chain reaction and based restriction fragment length polymorphism methods. During 6 years of follow-up, 36 violent offenders with mild MR were investigated. Thirty-six control volunteers were included in the study as a control group. H/L polymorphism of the COMT gene was investigated in these two groups. In conclusion, the COMT gene genotype distribution and allele frequency is not significantly different between the two groups (> 0.05). This result suggests that the H/L polymorphism of the COMT gene does not show an association with the potential of “commits-violent offense” of Turkish subjects with mental retardation, compared with control group.