Abstract
AbstractThe sex crimes that were reported in the Taiwan area have increased seven to ten folds for the last fifteen years (1981 to 1996). The increasing severity of sex crime urge new studies of factors that underline sex crime. According to the present research, these factors can be proposed to be cultural and personal. While the cultural factors have been well studied, the relation studies of sex crime and the personal factors have been limited to criminals’ characteristics, for example, anger, sexual aggressive, novel-seeking, anti-social, depressive and anxiety. Langevin (1998) indicated that rapes are associated with variations of endocrine and nerve systems. In the present study, it is the first time that the relationship of gene and sex crime being considered. Since the exact reason of sex crime remain obscure, we choose genes that affect criminals’ behavior, including DRD4 (novel-seeking, anti-social and mental disorder), DRD2 (sexual aggressive), MAOA, COMT (violent), HTR1A, HTR2C (anxiety, depressive). These genes are considered as candidate genes for genetic analysis of sex crime.In this research, blood samples were taken from 220 male criminals and 200 male control people. The genomic DNA was purified from their blood and was pooled as two groups: rape and normal. The DNA spanning chromosomal markers was amplified by polymerase chain reaction (PCR). The polymorphism was displayed by restriction fragment length polymorphism (RFLP) or variation number tandem repeat (VNTR) for different markers. The allelic frequencies of each gene were compared between rapists and normal male. The statistical results indicated different distribution of polymorphisms of DRD2, MAOA and COMT between the two groups (p<0.05). The rape group was subdivided into four categories by FBI discipline. The third category showed even stronger correlation with COMT allele than the rape group (p value shifted from 0.010 to 0.0097). Conclusively, the alteration in DRD2, MAOA or COMT made those rapists prone to commit crime.