Search Results (304)

This review paper presents a comprehensive overview of DNA preservation in hard tissues (bones and teeth) for applications in forensic and archaeogenetic analyses. It presents bone structure, DNA location in bones and teeth, and extensive information about postmortem DNA location and preservation. Aged bones are a challenging biological material for DNA isolation due to their low DNA content, degraded DNA, and the potential presence of PCR inhibitors. In addition, the binding of DNA to the mineral matrix necessitates the inclusion of a demineralization process in extraction, and its contribution to the resulting increase in both DNA quality and quantity is explained. Guidelines and recommendations on bone sample selection to obtain higher DNA yields are discussed in terms of past, recent, and possible future recommendations. Interskeletal and intraskeletal differences in DNA yield are also explained. Recent studies have shown that current recommendations for the genetic identification of skeletal remains, including femurs, tibias, and teeth, may not be the most effective sampling approach. Moreover, when mass disasters and mass graves with commingled skeletal remains are considered, there is a greater possibility that the recommended set of skeletal elements will not be available for sampling and subsequent genetic testing. This review highlights interskeletal and intraskeletal variability in DNA yield, with a focus on studies conducted on poorly preserved skeletal remains, including both postwar (1945) victims from Slovenia and ancient human skeletons. Special emphasis is placed on anatomical differences and potential mechanisms influencing DNA preservation, as demonstrated in research on both modern and historical skeletons. Finally, the petrous part of the temporal bone and tooth cementum were reviewed in greater detail because they have been recognized as an optimal sampling type in both ancient DNA studies and routine forensic case analyses. Our experiences with the Second World War and archaeological petrous bones are discussed and compared to those of other bone types. Full article

The postmortem interval (PMI), defined as the time elapsed between death and the discovery or examination of the body, is a crucial parameter in forensic science for estimating the time of death. There are many ways to measure the PMI, such as Henssge’s nomogram, which uses rectal temperature measurement; livor mortis; rigor mortis; and forensic entomology. However, these methods are usually affected by various conditions in the surrounding environment. The purpose of the present study was to compare molecular genetics and histological changes in the brain and skeletal muscle tissues of SD rats over increasing periods of time after death. For the PMIs, we considered 0 h, 6 h, 12 h, 24 h, 36 h, 48 h, 4 days, 6 days, 8 days, 10 days, 14 days, and 21 days and compared them at 4 °C and 26 °C. Hematoxylin and Eosin (H&E) staining was performed to observe tissue changes. Morphological tissue changes were observed in cells for up to 21 days at 4 °C, and cell destruction was visually confirmed after 14 days at 26 °C. Total RNA (tRNA) was isolated from each tissue sample, and complementary DNA (cDNA) was synthesized. A reverse transcription quantitative PCR (RT-qPCR) SYBR Green assay targeting three types of housekeeping genes, including Gapdh, Sort1, B2m, and 5S rRNA, was performed. The results showed that Gapdh and 5S rRNA were highly stable and could be better RNA targets for estimating the PMI in brain and skeletal muscle tissues. Conversely, Sort1 and B2m showed poor stability and low expression levels. In conclusion, these molecular biomarkers could be used as auxiliary indicators of the PMI in human, depending on the stability of the marker. Full article

Background: The success of forensic genetics has led to considerable numbers of DNA samples that must be stored. For example, the genetic casework unit of the forensic institute of the French gendarmerie analyzes more than 70,000 casework samples per year mainly from swabs that are fully consumed during DNA extraction. The only way to process further analyses is to preserve DNA. Currently, the most common technique used for the long-term preservation of DNA is to freeze the extracted DNA at −20 °C or −80 °C. However, this preservation method involves significant constraints (large equipment), risks (equipment failure), and is not ecologically sustainable due to its high energy consumption. Many solutions for DNA preservation at room temperature exist based either on fibrous supports or on anhydrobiosis. However, few studies have examined the efficiency of these systems in preserving very-low DNA amounts, such as those in forensic samples (≤1 ng), while ensuring full recovery and the ability to retest the samples many years later. Methods: We choose to evaluate the ability of the anhydrobiosis technology from GenTegra^® LLC to preserve DNA extracts from one month to one accelerated year from different DNA quantities (from 1 ng to 0.2 ng) and sources (NIST, mocked samples, and true casework mixtures). We studied the quantity, integrity of DNA, and also the quality of the STR genetic profiles obtained. Results and Conclusions: Our results prove the high potential of this technology to preserve and to allow an effective recovery of the DNA extracts for forensic purposes. Full article

Background: Forensic investigation of child homicides presents unique challenges due to the vulnerability of children and the complexity of distinguishing between natural, accidental, and intentional manner of death. A multidisciplinary approach integrating traditional forensic methods with emerging technologies is crucial to ensure accurate diagnosis and effective legal outcomes. Methods: This review examines current and emerging forensic techniques used in neonate, infant, and older child homicide investigations. It highlights advancements in postmortem imaging, histological examination, microbiological analysis, toxicology, and molecular autopsy. Results: Traditional forensic autopsy remains the cornerstone of child homicide investigations, providing critical insights into external and internal injuries. Histological examination enhances diagnostic accuracy by detecting microscopic evidence of trauma and infectious diseases. Postmortem imaging techniques are complementary for better identifying fractures, soft tissue injuries, and vascular abnormalities. Forensic toxicology plays a key role in detecting poisoning, while postmortem microbiology aids in identifying infectious causes of death. Furthermore, advancements in molecular autopsy and genetic testing have significantly enhanced the identification of hereditary conditions linked to sudden unexplained deaths in children, especially in cases involving multiple child fatalities within the same family, where forensic investigations are needed to accurately differentiate between natural causes and potential criminal involvement. Conclusions: A multidisciplinary approach incorporating traditional autopsy with postmortem imaging, histological examination, toxicology, postmortem microbiology, and molecular autopsy is essential for comprehensive forensic analysis, promoting both justice and prevention of fatal child abuse/homicide. Future research should focus on standardizing forensic protocols and exploring the potential of artificial intelligence (AI) in forensic investigations. Full article

In this study, 172 Single-Nucleotide Polymorphisms (SNPs) (94 identity-informative SNPs, 56 ancestry-informative SNPs, and 22 phenotypic-informative SNPs) included in the ForenSeq™ DNA Signature Prep kit/DNA Primer Mix B (Verogen) were used for genotyping DNA samples from a population of twenty-one unrelated subjects, native to Northeast Italy. SNP sequencing was performed with the MiSeq FGx™ Forensic Genomics System (Illumina-Verogen), and data were analyzed using the Universal Analysis Software (UAS) v1.2. Raw data underwent further examination with STRait Razor v3 (SRv3) to compare the target SNPs’ genotype calls made with UAS and to identify the presence of microhaplotypes (MHs) due to SNPs associated with the same target SNP’s amplicon. The allele (haplotype) frequencies, Hardy–Weinberg equilibrium, linkage disequilibrium, number of effective alleles (A_e), and relevant forensic statistic parameters were calculated. Among the 172 SNPs evaluated, 45 unique microhaplotypes were found, comprising a novel sequence variant never previously described. The presence of MHs resulted in an 8.00% rise in the typologies of unique sequences, leading to changes in A_e. Notably, for 12 out of the 94 iiSNPs, the values of A_e exceeded 2.00, which is generally associated with a higher expected heterozygosity and increased power of discrimination. Full article

This study aimed to determine the allele frequencies and genetic diversity of 21 autosomal short tandem repeat (STR) loci from the Expanded U.S. Core Loci and European Standard Set in the Romanian population. A random sample of 928 unrelated men from all Romanian counties was analyzed using the Investigator 24plex QS and Investigator 24plex GO! Kits (Qiagen). The genotypes were determined, and the allele frequencies were calculated using the STRidER tool. The results provide updated population genetic data for the Romanian population, which is essential for accurate calculation of DNA evidence weight in forensic casework. Full article

Forensic genetics has experienced remarkable advancements over the past decades, evolving from the analysis of a limited number of DNA segments to comprehensive genome-wide investigations. This progression has significantly improved the ability to establish genetic profiles under diverse conditions and scenarios. Beyond individual identification, forensic genetics now enables the inference of physical traits (e.g., eye, hair, and skin color, as well as body composition), biogeographic ancestry, lifestyle habits such as alcohol and tobacco use, and even the transfer of genital microbiomes post-coitus, among other characteristics. Emerging trends point to a future shaped by the integration of cutting-edge technologies, including CRISPR-Cas systems, artificial intelligence, and machine learning, which promise to further revolutionize the field. This review provides a thorough exploration of forensic genetics, tracing its evolution from its foundational methods (past) to its diverse modern applications (present) and offering insights into its potential future directions. Full article

Noninvasive prenatal paternity testing (NIPPT) is a crucial tool in forensic contexts, particularly in cases involving post-rape pregnancies. It enables judicial authorities and victims to promptly address these situations by determining the paternity of the fetus within a few weeks of pregnancy. NIPPT relies on the analysis of cell-free fetal DNA (cffDNA) found in the maternal bloodstream. However, the abundance of maternal DNA presents a significant challenge in detecting fetal DNA. As a result, research has focused on improving methods for isolating or enriching fetal DNA and, specifically in the context of forensic genetics, on the development of suitable genetic markers. The use of Single Nucleotide Polymorphisms (SNPs) along with novel compound markers or composite multiplexes, has shown promising results. Despite significant advances, partly driven by the increased use of Massive Parallel Sequencing (MPS), challenges remain in validating markers-based NIPPT assays for forensic casework. Further studies are required to enhance the sensitivity of these tests, particularly during the early stages of pregnancy, such as the first trimester. Additionally, improving and standardizing statistical frameworks for result evaluation and interpretation is essential to ensure compatibility with forensic standards. Full article

The postmortem interval (PMI) is defined as the time interval between physiological death and the examination of the corpse, playing a critical role in forensic investigations. Traditional PMI estimation methods are often influenced by subjective and environmental factors. Circular RNAs (circRNAs), known for their stability, abundance, and conservation in brain tissue, show promise as biomarkers for PMI estimation. However, research on circRNAs in this context remains limited. This study aimed to develop PMI estimation models using circRNAs across multiple temperatures. By employing semi-quantitative reverse transcription-PCR, circTulp4, circSlc8a1, and circStrn3 were identified as reliable biomarkers for mouse brain tissue. Mathematical models were constructed using the reference genes 28S rRNA, mt-co1, and circCDR1as. At 4 °C, most equations had p-values below 0.05, with the equation using circSlc8a1 as a marker exhibiting the highest goodness of fit. Validation results indicated that the equation using circTulp4 as the reference gene had the highest accuracy. When applying the combined aforementioned three circRNAs, the equation using circCDR1as as the reference gene showed better accuracy. At 25 °C, all equations had R² values greater than 0.86, but most cubic equations had p-values above 0.05. Validation results demonstrated that the circTulp4/mt-co1 equation had the highest accuracy. When applying combined circRNAs, the R² values improved, and long-term PMI estimation was more accurate than short-term PMI estimation. At 35 °C, the linear equations had significantly poorer goodness of fit compared to nonlinear equations, and nonlinear equations exhibited better accuracy than linear equations. When applying the combined aforementioned three circRNAs, the accuracy of the three reference genes was similar, and the accuracy of long-term PMI estimation was consistently higher than that of short-term estimation. For the three-dimensional models, all R² values exceeded 0.75 with p-values significantly below 0.0001. Validation results demonstrated higher accuracy at 25 °C and 35 °C, with superior performance for long-term PMI estimation. In summary, this study constructed PMI estimation models under multiple temperature conditions based on highly expressed circRNAs in mouse brain tissue, highlighting circTulp4, circSlc8a1, and circStrn3 as novel biomarkers. These findings offer a complementary tool for PMI estimation, particularly for long-term PMI estimation. Full article

Microhaplotypes (MHs) are a novel class of genetic markers, exhibiting features that position them as an alternative to STRs and SNPs in addressing challenges commonly encountered in forensic investigations. Additionally, MHs can also offer valuable insights for ancestry inference. However, due to the novelty of MHs, extensive research in different global populations is required before implementation in forensic casework and general research. In this study, individuals from Afghanistan and Somalia were characterized with the Ion AmpliSeq™ MH-74 Plex Research Panel previously developed for forensic genetic purposes. A total of 84 Afghan and 89 Somalian samples were sequenced on the Ion GeneStudio™ S5 System. This led to the identification of 32 and 42 single nucleotide variants in the Afghan and Somalian populations, respectively, that were not included in the former MH definitions. Most of the observed variants were considered to be rare occurrences, being observed one or two times in the dataset. The average values of the effective number of alleles (A_e) were 3.7 for Somalia and 3.6 for Afghanistan—pointing to elevated intrapopulation diversities compared to Europeans. Other parameters (H_o, H_e, PIC, PD, and PE) consistently showed higher average values in the Afghans and Somalis compared to the previously studied populations. PCA and STRUCTURE analyses with 1000 Genomes samples assigned the Somalis to a different cluster than the other sub-Saharan African populations. The analyses also showed higher European and East Asian co-ancestry in the Afghans than in the remaining South Asian populations. The capability of the MH-74 plex to address common kinship problems was evaluated through computational simulations, considering generic thresholds differing by one order of magnitude to assess the FDRs. The median LR > 10¹³ for true siblings when the hypotheses ‘full siblings’ and ‘unrelated individuals’ were compared. As expected, the median LRs were much lower for simulated half-siblings and cousins. This work evaluated the forensic potential of MHs in understudied populations. Overall, the studied panel was versatile and capable of being applied in different forensic applications. Full article

Traces of potential contact from a perpetrator for evidence are one of the most frequently secured groups of evidence during the examination of the crime scene and during the examination of material in forensic laboratories. By far the most common way to secure the above-mentioned traces is the use of swabs. The literature reports indicate promising results from the use of adhesive materials for securing contact marks. The products currently on the market are not dedicated to forensic genetics or cause problems with the recovery of protected DNA at the stage of DNA isolation in the laboratory. The aim of this study was to determine the effect of conditions from an accelerated aging process carried out under simulated laboratory conditions (with aging factors as follows: UV radiation, temperature, and humidity level) on the physico-mechanical properties and chemical resistance of adhesive films made of polyethylene (PE) and polypropylene (PP). As part of the research, the influence of storage conditions on the physico-mechanical properties and chemical resistance of developed foil materials used to secure forensic traces was developed and verified. The research was carried out in conditions similar to the real ones, conducting tests of accelerated aging with the following factors: temperature, humidity, and UV radiation. Full article

Background/Objectives: Identification of human remains is of utmost importance for criminal investigations and providing closure to the families. The reconstruction of a biological profile of the individual will narrow down the list of candidates for identification. From another perspective, facial approximations performed by a forensic artist can provide investigative leads, with the identity being confirmed by primary or secondary methods of identification. In recent years, DNA analysis has evolved, trying to create a portrait of the perpetrator/victim based on External Visible Characteristics (EVCs), the color of the eyes, hair, and skin and Biogeographical ancestry (BGA), called DNA phenotyping. Despite these advances, currently, there are no studies integrating the biological profile performed by forensic anthropologists, the facial approximation created by forensic artists and EVCs determined by DNA. The goal of this work was to integrate these three investigative leads to enhance the possibility of human identification. Methods: Five donated remains from Mercyhurst were studied through these approaches: reconstruction of biological profile, facial approximation and estimation of EVCs based on previous studies. Results: Our results indicated the feasibility of integrating this biological profile and EVCs data into the facial approximation developed by the forensic artist, aiming to an enhance portrait of the remains. In a second phase of this project, the accuracy of the integrated facial approximation will be assessed. Conclusions: This study pointed out the importance of an interdisciplinary approach towards the identification of human remains, as well as the combination of current methods with new technologies. Full article

Cardiovascular diseases increase among pregnant women and complicate 1–4% of pregnancies worldwide. The incidence of maternal deaths due to cardiovascular causes has increased dramatically, rising from 3% three decades ago to 15% in recent years. The aim of this study is to provide a comprehensive overview of the current status of knowledge in sudden maternal death (SMD) described in the literature and to present two cases of autopsy findings in sudden cardiac death in pregnant women. Among the most common causes of sudden maternal deaths are peripartum cardiomyopathies, aortic dissection, acute myocardial infarction, arrhythmias, ischemic heart disease, and coronary artery dissection, and among the less common causes, we list coronary artery dissection, congenital heart diseases, valvulopathies, hypertension, fibroelastosis, and borderline myocarditis. The Centers for Disease Control and Prevention (CDC) reported that over 80% of pregnancy-related deaths were preventable. To reduce the number of maternal deaths caused by cardiovascular diseases, the implementation of specialized multidisciplinary teams has been proposed. Molecular biology techniques are proving their effectiveness in forensic medicine. PCR or DNA sequencing can be utilized in “molecular autopsy”, which holds particular value in cases of sudden death where the forensic autopsy is negative but there is a suspicion that death was caused by arrhythmia. Susceptibility genes can be analyzed, such as KCNQ1, KCNH2, KCNE1, and KCNE2, which are involved in long QT syndrome, the RYR2 gene implicated in catecholaminergic polymorphic ventricular tachycardia type 1, or the SCN5A gene associated with Brugada syndrome. Early identification of risk factors involved in sudden maternal death prenatally and during pregnancy is essential. At the same time, genetic determinations and molecular biology techniques are absolutely necessary to prevent the occurrence of sudden deaths among close relatives. Full article

Background: Apical hypertrophic cardiomyopathy (ApHCM) is a distinct variant of hypertrophic cardiomyopathy (HCM). Few studies have focused on the genetic determinants of this subtype. We aimed to investigate the genetic basis of apical hypertrophy in a Swedish cohort. Methods–Results: Longitudinal data on 58 unrelated index patients with ApHCM from the Southeast healthcare region in Sweden from 2010 to 2024 were assessed retrospectively. Additionally, the original raw data from genetic testing were re-evaluated using AI-based Emedgene software. Patients were 47 ± 14 years old, and 60% males. A total of 72.4% had the pure apical type and the remaining had the mixed phenotype, dominant distal. In the cohort, 50/58 (86.2%) underwent genetic testing, of whom 7/50 (14%) were considered genotype positive for a pathogenic/likely pathogenic variant, mainly in MYH7 (43%) and in the non-sarcomeric ALPK3 gene (28.6%). A re-evaluation of the original data from genetic testing identified a previously unreported variant in the skeletal muscle α-actin (ACTA1) gene. Overall, 21 of 58 patients (36.2%) had HCM-related events during their disease course: 10% had a stroke, and 12% had heart failure. Atrial fibrillation was present in 41.4% and non-sustained ventricular tachycardia occurred in 29.3% of the patients. Apical aneurysm was observed in 17.2% of cases. Patients with a positive genotype were more likely to have a positive family history of HCM compared to those with a negative genotype (p = 0.020). Conclusions: In ApHCM, a positive genotype was found less frequently compared to classic HCM. Only 14% of patients with ApHCM were found to be genotype positive, indicating that apical hypertrophy represents a genetically unique population with low risk of mortality. Nevertheless, patients with ApHCM faced higher rates of atrial fibrillation, ventricular arrhythmias, and apical aneurysms. Full article

Background/Objectives: The Y chromosome is a crucial tool in forensic genetics due to its unique characteristics, such as its haploid inheritance and lack of recombination. Y-STRs (short tandem repeats on the Y chromosome) are widely used for identifying male genetic profiles in DNA mixtures, especially in sexual assault cases where high levels of female DNA hinder autosomal analysis. This study evaluates the applicability of Y-STRs in forensic investigations, addressing their limitations and the impact of advanced technologies, such as rapidly mutating Y-STRs (RM Y-STRs). Methods: A comprehensive literature review was conducted to analyze existing knowledge on the application of Y-STRs in sexual crimes. The study also examines the role of population databases, such as YHRD, in estimating haplotype frequencies and enhancing forensic reliability. Results: Y-STR analysis proves essential for male DNA identification in complex mixtures, with RM Y-STRs enhancing discriminatory power. However, limitations persist, particularly in cases involving closely related male lineages. The population database coverage remains insufficient in regions like Cape Verde, affecting forensic reliability. Case studies demonstrate Y-STR effectiveness in solving cold cases and sexual crimes, reinforcing the need for expanded databases and methodological advancements. Conclusions: Y-STRs play a fundamental role in forensic genetics, particularly in sexual assault investigations. Their integration with advanced sequencing technologies and expanded databases is critical for improving forensic accuracy. Ethical considerations regarding genetic data privacy and potential discrimination must be addressed through clear regulations and forensic best practices. Full article