Analysis of global variability in 15 established and 5 new European Standard Set (ESS) STRs using the CEPH human genome diversity panel

The CEPH human genome diversity cell line panel (CEPH-HGDP) of 51 globally distributed populations was used to analyze patterns of variability in 20 core human identification STRs. The markers typed comprised the 15 STRs of Identifiler, one of the most widely used forensic STR multiplexes, plus five recently introduced European Standard Set (ESS) STRs: D1S1656, D2S441, D10S1248, D12S391 and D22S1045. From the genotypes obtained for the ESS STRs we identified rare, intermediate or off-ladder alleles that had not been previously reported for these loci. Examples of novel ESS STR alleles found were characterized by sequence analysis. This revealed extensive repeat structure variation in three ESS STRs, with D12S391 showing particularly high variability for tandem runs of AGAT and AGAC repeat units. The global geographic distribution of the CEPH panel samples gave an opportunity to study in detail the extent of substructure shown by the 20 STRs amongst populations and between their parent population groups. An assessment was made of the forensic informativeness of the new ESS STRs compared to the loci they will replace: CSF1PO, D5S818, D7S820, D13S317 and TPOX, with results showing a clear enhancement of discrimination power using multiplexes that genotype the new ESS loci. We also measured the ability of Identifiler and ESS STRs to infer the ancestry of the CEPH-HGDP samples and demonstrate that forensic STRs in large multiplexes have the potential to differentiate the major population groups but only with sufficient reliability when used with other ancestry-informative markers such as single nucleotide polymorphisms. Finally we checked for possible association by linkage between the two ESS multiplex STRs closely positioned on chromosome-12: vWA and D12S391 by examining paired genotypes from the complete CEPH data set.     

Child sex tourism: extending the borders of sexual offender legislation

Child sex tourism, the act of traveling to engage in sexual acts with minors, plagues developing nations worldwide. Several laws have been passed internationally in recent years designed to curtail this practice. Government entities and human rights organizations have driven these efforts. United States citizens represent a significant proportion of participants in child sex tourism. The PROTECT Act of 2003 prohibits United States citizens from participating in sexual acts with minors while traveling, and establishes extraterritorial jurisdiction. The case of Michael Lewis Clark, the first United States citizen convicted under this legislation, is highlighted. Child sex tourism poses unique issues to courts that will require ongoing clarification as challenges arise. This article discusses potential future challenges, describes strategies to address this problem, and relates this issue to psychiatry. Mental health providers may have the role of evaluating both the victims and perpetrators of child sex tourism. The authors propose a classification system for offenses and an initial list of topics to discuss with victims. The authors also describe the proper mechanism for reporting United States citizens suspected of participating in child sex tourism.