Forensic science international. Genetics最新文献

The IPEFA model was developed for organizing online training and education events as applied by the International Society for Forensic Genetics (ISFG). It consists of five phases: 1) Input, 2) Preparation, 3) Execution, 4) Feedback, and 5) Assessment. This document details these phases and shows IPEFA's first practical application to the 2023 edition of the virtual ISFG Summer School. Through sharing the experiences, we aim to provide transparency and engage with potential participants and teachers to (virtual) training and education events as organized by the ISFG. The model may also be useful for others organizing (online) events. We have experienced that evaluation of events with input and feedback from both the (potential) participants and teachers is essential for successful training and education. This takes time which is limited in everyone's busy agenda's and may therefore not always be performed with the care it requires. Since these aspects are crucial, however, we aim to keep following the principles as outlined in the IPEFA model.

DNA methylation patterns have emerged as reliable markers for age estimation, offering potential applications in forensic investigations, namely, in cases where there is no information about a possible suspect, in the identification of victims of mass disasters, or in immigration cases when assessing the age of individuals seeking asylum. This study aimed to evaluate the 11-CpG panel proposed by Aliferi et al. (2022) for age estimation. During the implementation phase, the ELOVL2 amplicon from the original work was replaced with a shorter fragment, and the two PCR multiplexes were optimized by changing the amplicons and primer conditions of each multiplex. The technical performance of the optimised assay was assessed using artificially methylated DNA standards. Robust quantification of the methylation levels at the 11 CpG sites was observed. Sensitivity tests demonstrated that DNA inputs down to 10 ng could produce reliable methylation quantification. Using the optimised panel, 148 Danish blood samples (18 - 68 years of age) were typed for their methylation status at the 11 CpG sites. Results showed that the DNA methylation at the 11 CpG loci was significantly correlated with age (0.68 ≤ r ≤ 0.88) in the Danish sample set, confirming the potential of the 11 CpGs in age prediction. A Danish age prediction model was constructed using 108 of the Danish blood samples and a support vector machine with polynomial function (SVMp). The performances of the new model and the original model based on UK individuals were compared using the remaining 40 Danish blood samples. Comparing the published model to the one developed in this study gave similar results with mean absolute errors (MAE) of 3.28 and 3.35, respectively. However, the original model showed a bias in the age predictions, underestimating the age by an average of 1.53 years in the Danish samples. This bias towards underestimation was not observed in the newly developed age prediction model based on Danish individuals. In summary, this assay provides a reasonably accurate age estimation of a single-source donor, if the sample material is blood and more than 10 ng of nuclear DNA can be extracted from the sample.

Human identification by forensic DNA profiling primarily relies on the analysis of short tandem repeat markers (STRs) and Amelogenin or other sex determining markers. The resultant DNA profiles can be compared directly between evidence and reference samples or indirectly (i.e., kinship) between human remains and family reference samples. Although Amelogenin serves as a phenotypic marker for biological sex, it is often considered innocuous, and the biological sex derived from this marker is routinely reported and/or uploaded to national DNA databases. However, biological sex does not necessarily align with gender identity, and chromosomal anomalies may affect the presentation of biological sex. Biological sex is genetically determined and assigned at birth based on anatomical features, whereas gender identity is an individual expression that may change over time and may not correspond with biological sex. This paper highlights how the differences between biological sex and gender identity can potentially impinge on individual privacy. Beyond gender differences, genetic anomalies related to the presentation of biological sex can occur, and the consequences of revealing such anomalies may have far-reaching implications for the individuals involved. Disclosing biological sex in a forensic DNA profile does not take into account the ramifications for persons or their families with genetic anomalies related to sex chromosomes (which may or may not be known to the individual), transgender transformations (which may or may not have been disclosed by the individual), or gender-identity expressions that do not correspond with biological sex. Through the presentation of case scenarios, while knowledge of biological sex may be important for operational forensic DNA laboratories and critical in certain cases, it is often not relevant to criminal investigations, courtroom deliberations, or public disclosure. It behoves all of us to understand that the dissemination of biological sex data in the public domain, especially in contexts where disclosure is unnecessary, may impact individual privacy. In light of the current understanding and growing impact of gender identity, it is recommended with all due speed that (1) 'biological sex' and 'gender' be recognised as separate concepts, not to be used synonymously nor interchangeably; (2) definitions of a DNA profile be reviewed and more clarity added; and (3) policies and protocols be developed to restrict such information from reports and court proceedings (i.e., public arenas), when not relevant, thereby reducing unwarranted intrusions into individual privacy and acknowledging the right to keep biological sex private and control how and when this personal information is shared.