性侵害加害人之多巴胺基因系統群的關聯性研究

Association Study of Dopamine-Related Genes in Sexual Offenders

白崇彥(Chung-Yen Pai) ； 黃景明(Jing-Ming Huang) ； 陳凱華(Kai-Hua Chen) ； 楊秋和(Chiou-Herr Yang) ； 詹志文(Zhi-Wen Zhan)

《犯罪與刑事司法研究》 6期 (2006/03) Pp. 99-133

https://doi.org/10.29861/CCJI.200603.0003

摘要

According to the studies of molecular genetics, many characteristics of an individual have been determined early before being born. Recently, literatures reveal that the neurotransmitter of dopamine is closely associated with human sexual arousal, aggressive and impulsive behavior. The dopamine neurotransmitter would be mainly digested by the genes of COMT (catechol-O-methyltransferase) and MAO (monoamine oxidase), which is divided into two subtypes of MAOA and MAOB. The mutation and/or variations in the genes of MAO, COMT and dopamine receptors (DRD) may cause a change or a loss in genetic functions, influencing the concentration of dopamine in brain, and leading to the development of psychiatric abnormal behaviors. Sexually aggressive behavior has the nature of impulsiveness and violence. The purpose of this study was thus to evaluate the possible association of sexually aggressive behavior and candidate genes. It was hypothesized that over-expressed dopamine in brain could play a role in susceptibility to the sexually violent behaviors. The association study was performed on the 265 male inmates (sexual offenders) from Taipei Prison and the 240 control subjects, which were the students of Central Police University. Four functional markers of MAOA-uVNTR, MAOA-Fnu4H1, MAOB-SNP, COMT-RFLP, and one DNA marker of DRD2-Taq1A were investigated. After DNA extraction, analyses of polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and electrophoresis were performed on the case and control groups. The data of the genotypic and allelic types from the two groups were analyzed using the chi-square test. The results showed that statistical significance (p＜0.05) was observed on genotype and allelic type of MAOA-uVNTR(x^2=12.737, p=0.00065) and MAOA-Fnu4H1(x^2=9.38, p=0.002) between the case and the control group. The significance was also found on the MAOB-SNP between the control and repeatedly sexual criminals (x^2=4.494, p=0.034). No significance was seen on the genotype and allele type of the two markers of COMT-RFLP and DRD2-Taq1A. Additionally, the haplotype analyses of the MAOA-Fnu4H1 and MAOB-SNP, but not the MAOA-uVNTR, showed a positive effect on the association. These results implicated that the three functional markers (MAOA-uVNTR, MAOA-Fnu4H1 and MAOB-SNP loci) could play a role in promoting the exhibition of sexually violent behaviors. This study might provide a better understanding for the relationship between sexually violent behaviors and the regulation of the candidate genes.

關鍵字

性暴力 ； 多巴胺相關基因群 ； 單胺氧化酶 ； 關聯性研究

並列摘要

According to the studies of molecular genetics, many characteristics of an individual have been determined early before being born. Recently, literatures reveal that the neurotransmitter of dopamine is closely associated with human sexual arousal, aggressive and impulsive behavior. The dopamine neurotransmitter would be mainly digested by the genes of COMT (catechol-O-methyltransferase) and MAO (monoamine oxidase), which is divided into two subtypes of MAOA and MAOB. The mutation and/or variations in the genes of MAO, COMT and dopamine receptors (DRD) may cause a change or a loss in genetic functions, influencing the concentration of dopamine in brain, and leading to the development of psychiatric abnormal behaviors. Sexually aggressive behavior has the nature of impulsiveness and violence. The purpose of this study was thus to evaluate the possible association of sexually aggressive behavior and candidate genes. It was hypothesized that over-expressed dopamine in brain could play a role in susceptibility to the sexually violent behaviors. The association study was performed on the 265 male inmates (sexual offenders) from Taipei Prison and the 240 control subjects, which were the students of Central Police University. Four functional markers of MAOA-uVNTR, MAOA-Fnu4H1, MAOB-SNP, COMT-RFLP, and one DNA marker of DRD2-Taq1A were investigated. After DNA extraction, analyses of polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and electrophoresis were performed on the case and control groups. The data of the genotypic and allelic types from the two groups were analyzed using the chi-square test. The results showed that statistical significance (p＜0.05) was observed on genotype and allelic type of MAOA-uVNTR(x^2=12.737, p=0.00065) and MAOA-Fnu4H1(x^2=9.38, p=0.002) between the case and the control group. The significance was also found on the MAOB-SNP between the control and repeatedly sexual criminals (x^2=4.494, p=0.034). No significance was seen on the genotype and allele type of the two markers of COMT-RFLP and DRD2-Taq1A. Additionally, the haplotype analyses of the MAOA-Fnu4H1 and MAOB-SNP, but not the MAOA-uVNTR, showed a positive effect on the association. These results implicated that the three functional markers (MAOA-uVNTR, MAOA-Fnu4H1 and MAOB-SNP loci) could play a role in promoting the exhibition of sexually violent behaviors. This study might provide a better understanding for the relationship between sexually violent behaviors and the regulation of the candidate genes.

並列關鍵字

sexual violence ； dopamine-related genes ； monoamine oxidase ； association study