Forensic Science International: Genetics Supplement Series最新文献

Since 2018, investigative genetic genealogy (IGG) has been used as a novel technology to solve cold cases. But IGG presents several ethical issues regarding privacy and regulation. IGG has never been used in Brazil although the number of direct-to-consumer (DTC) ancestry tests has been increasing and its users use open platforms in which IGG can be applied, such as GEDMatch, being susceptible to the same ethical problems as in those countries where IGG is being applied. We conducted an online survey with 166 clients of DTC ancestry tests (DTC) and 35 Brazilian CODIS Administrators (ADM) to evaluate their knowledge about the forensic application of genetic genealogy, their opinion about it, and a possible application in Brazil. Both groups support using IGG in violent crimes and missing persons (58.5% of DTC and 34.3% of ADM) but also showed concerns about the legislation and ethical issues (78.9–55.4% DTC and 97–65% ADM). Furthermore, 20% of ADM were against the use of this technique compared to the DTC (4%), probably due to the lack of knowledge of the methodology, its scope, and limitations. These results show the need to broaden the discussion on the IGG in various sectors of society.

FIDL is a fast and automated DNA identification line which represents a series of software solutions automating the process from raw capillary electrophoresis data to reporting. This retrospective study provides insight in the numbers of cases, turnaround time, results compared to the standard workflow and the benefits automation has in a large volume workflow.

Interpretation of ancestry informative markers (AIMs) in a forensic case can be time-consuming as different tools are used that need to be initiated separately. We develop the ForAPP; an open-source pipeline (running offline) that initiates multiple ancestry prediction analyses and summarizes results in an interactive interface for interpretation of autosomal ancestry-informative markers.

Orogen advances the science of relationship prediction by using Ped-sim, which improves upon previous models by incorporating crossover interference and sex-specific genetic maps. The Orogen tool provides accurate relationship predictions for a wide range of relationship types. It properly differentiates between close relatives at 23andMe, which is a newly available functionality for standalone tools. It provides new granularity of close relationships by showing the differences between paternal and maternal sides and in-group relationship types.

Latent DNA detection has the potential to transform aspects of DNA collection at scenes and from items. In the absence of being able to visualise the location of cellular material, all collection of samples at crime scenes is currently performed blind. With the advent of the application of a nucleic acid staining dye, the DNA within skin cells (commonly called keratinocytes and corneocytes) can be visualised. Diamond Dye fluoresces when it binds to the backbone of DNA. This fluorescence can be recorded using a simple mini-microscope allowing the location and number of cells to be recorded. The potential to visualise cells on a wide range of substrates opens the possibility to target sample collection and to triage samples for further analyses to only those containing DNA. Diamond Dye has been found to be safe at the concentration used, inexpensive, available commercially, easy to apply, is highly sensitive, and does not inhibit further analyses such as PCR. This work presented at the ISFG congress gives an overview of the current developments on using DNA staining dyes to record the number of cells present on a wide range of substrates. It is essential to firstly understand the composition of cellular material deposited by touch, where it originates and the relative composition of corneocytes and cell-free DNA. Insight into the origins of touch DNA will be presented along with the staining of nuclei using a range of dyes to show corneocyte degradation. The presentation will cover how DNA binding dyes can be used to effectively triage sample collection, monitor cell collection using different swabs and tapes.

MicroHapulator’s empirical microhaplotype calling algorithm produces profiles well-suited for forensic analyst interpretation and probabilistic interpretation.

Finding fast and cheap strategies for DNA typing and human sample identification is of interest in forensic science. We report a new versatile alternative for molecular sex determination using Y-specific targets (TSPY, TTTY, alphoid regions, and Y-Amelogenin). This system uses an isothermal loop-mediated DNA amplification (LAMP) with a set of 6 primers for each target, designed to improve sensibility and specificity, and reducing detection time to only 45 min. Furthermore, detecting the different targets on the Y chromosome either individually or in combination revealed accurate results. Assay sensitivity was determined with a mixture of human female and male DNA at different concentrations to mimic forensic samples. Single primer sets showed high sensitivity at DNA concentrations ranging from 58.6 to 3.7 pg/µL. When a combined primers set was used, sensitivity yielded a detection as low as 0.1 pg/µL of male DNA, making it 10 times more sensitive than qPCR-DNA quantification kits. Finally, high specificity was observed when tested against 6 domestic species.

Cow, Bos taurus, and female buffalo, Bubalus bubalis, are considered sacred animals that are a part of rural livelihood in India. The purity of products from these bovine species has significant sentimental implications in the dairy and meat industry. Therefore, the mitochondrial DNA and the sex origin, targeting the X and Y chromosomes from these bovine species, were selected to design three multiplex real-time probe PCR assays: Hi-PCR® Cow Detection Kit (MBPCR184), Hi-PCR® Buffalo Detection Kit (MBPCR185) and Hi-PCR® Cattle Sex Determination Kit (MBPCR186). Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines were followed to perform different studies using reference control DNAs. An Internal Reagent Control (IRC) was part of every assay, thus ensuring a successful reaction. The assays were 100% specific, with no cross-amplification of the two bovine species. The amplification of the X chromosomal target was observed for male and female DNAs, whereas Y chromosome amplification was observed only for the male DNA. The assays were 100% specific to the target genes in these organisms with no non-specificity towards any other targets or organisms. The limit of detection for sex determination was 0.01 ng/µl, whereas the differential capability of the assay was 3 copies/µl and 30 copies/µl for Bos taurus and Bubalus bubalis, respectively. The assays were reproducible at 1 ng/µl genomic DNA with 95% CI. The assays are open and compatible with other brands of Real-Time PCR systems used in forensic labs. The experiments presented here verify that the developed real-time PCR assays are robust, produce reliable and reproducible results for detection and differentiation of Bos taurus and Bubalus bubalis and their sex even at low DNA concentrations.

The X chromosome has unique features, such as haplodiploid mode of genetic transmission, which can be crucial to complement autosomal profiling or to disentangle complex kinship problems. Indeed, for some cases (e.g. full- or paternal half-sisters, or paternal grandmother-granddaughter hypotheses), X-markers are expected to provide a similar or a higher power to the one obtained with autosomes in paternity/maternity investigations. Both theoretical and informatics frameworks for pairwise X-linked kinship analyses are well established for individuals with a regular number of chromosomes, but these are still lacking for individuals exhibiting an X chromosome aneuploidy, such as females with Triple X (47, XXX) syndrome. Indeed, this work was motivated by a real forensic case involving the evaluation with X-chromosomal markers of the hypotheses that two women were related either as paternal half-sisters or as unrelated, one of them showing a trisomy X. In this case, the analysis of X-chromosomal markers would yield stronger results than autosomes, as females had to share at least one identical allele in each analyzed X chromosome marker under the paternal half-sibling hypothesis, unless a mutation occurs. To fulfill this gap, we present in this work algebraic formulae for some genotypic configurations, which will allow quantification of the evidence on the referred cases. A general approach, comprising other X chromosome aneuploidies, kinship hypotheses, and genotypic configurations, is currently being developed by us. This work is the starting point to analyze X-chromosomal data under the scope of kinship problems, involving individuals with aneuploidies. This will improve the quantification of DNA evidence not only in forensic casework, but also in the field of medical genetics, whenever individuals with X-chromosomal aneuploidies are involved.