ABSTRACT
Recent studies have suggested an association of genetic and neurodevelopmental factors with development of paraphilia. In this case report on monozygotic twins with pedophilia, we aim to offer additional evidence indicating that genetic vulnerability may be a significant risk factor along with environmental influences on development of pedophilia. These twin pairs, who have been arrested for sexual offenses against boys, had experienced emotional and physical abuse during their childhood, and the older twin brother is reported to have a history of sexual abuse. Both showed homosexual tendencies, and the younger twin brother was also diagnosed as exhibitionism. This case implies greater involvement of genetic factors and associated vulnerabilities in the etiology of paraphilia, including pedophilia, than environmental factors such as childhood abuse. In the future, conduct of research will be needed in order to determine the biological markers related to the etiology of pedophilia.