Establishment and Application of a 42-plex Microhaplotype Assay in Forensic Genetics / 法医学杂志

Objective To establish and forensically verify a 42 microhaplotypes(mircohaps,MHs)mul-tiplex assay system based on next-generation sequencing(NGS),and to explore the application value of this system in the practice of forensic genetics.Methods A total of 42 highly polymorphic MHs were selected from previous studies,and sequenced by the MiSeq FGxTM platform to verify the repeata-bility,sensitivity,specificity,stability,and mixture analysis ability of the detection system.Through population genetic investigation of 102 unrelated Chinese Han individuals in Liyang City,Jiangsu Province,China,the application value of this system in forensic genetics was evaluated.Results The sequencing repeatability of the 42-plex MHs assay was 100%and the sensitivity was as low as 0.062 5 ng.The system had the ability to withstand the interference of indigo(≤2 500 ng/μL),humic acid(≤9 ng/μL),hemoglobin(≤20 μmol),and urea(≤200 ng/μL)and to detect mixtures of 2 people(1∶19),3 people(1∶1∶9)and 4 people(1∶1∶1∶9).Based on 102 individual data,the combined power of discrimination and the combined power of exclusion were 1-3.45×10-30 and 1-3.77×10-11,respectively,and the average effect value of alleles was 2.899.Conclusion The 42-plex MHs assay was successfully established in this study and this system has high repeatability and sensitivity,good anti-jamming ability and mixture analysis ability.The 42 MHs are highly polymorphism and have good application value in individual identification and paternity testing.

Research Progress on Biological Evidence Identification in Fire Scenes / 法医学杂志

Biological evidence is relatively common evidence in criminal cases,and it has strong pro-bative power because it carries DNA information for individual identification.At the scene of fire-related cases,the complex thermal environment,the escape of trapped people,the firefighting and res-cue operations,and the deliberate destruction of criminal suspects will all affect the biological evi-dence in the fire scene.Scholars at home and abroad have explored and studied the effectiveness of biological evidence identification in fire scenes,and found that the blood stains,semen stains,bones,etc.are the main biological evidence which can be easily recovered with DNA in fire scenes.In order to analyze the research status and development trend of biological evidence in fire scenes,this paper systematically sorts out the relevant research,mainly including the soot removal technology,appearance method of typical biological evidence,and possibility of identifying other biological evidence.This pa-per also prospects the next step of research direction,in order to provide reference for the identifica-tion of biological evidence and improve the value of biological evidence in fire scenes.

Feasibility study of individual identification based on superimposition of 2D-3D face images in Han individuals / 中国法医学杂志

Objective To explore the feasibility of individual identification based on the 2D-3D face image superimposition in Han individuals.Methods The 2D video surveillance images(including front,left and right side)and high-precision 3D face models of 10 Han individuals were collected,and Autodesk 3ds Max 2018 software was used to perform perspective matching on the 3D face models,and superimposed them on the 2D images,and the mean values of the distances between corresponding 11 feature points in the 2D-3D face images were calculated.The superimposition of 2D-3D face images from the same individual was defined as the matching group,and the superimposition of 2D-3D face images from different individuals was defined as the non-matching group.Results In general,the average distance ranges of the corresponding feature points between the matching group and the non-matching group did not overlap(P<0.05).Conclusion The non-overlapping mean range preliminarily indicates that the individual identification method based on the overlay comparison of 2D-3D face images described in this paper is feasible for Han individuals.

Process of Forensic Medicine in DNA Identification of Aged Human Remains / 法医学杂志

Skeleton and teeth are important biological samples. Due to their special structure and strong ability to resist degradation, they are ideal biological materials to retain DNA under natural condition. In many cases, such as historical figure identification, aged skeleton and teeth are usually the only biological samples. However, their DNA is in a state of trace, damage and degradation to different degrees, which requires special experimental treatment to achieve identification. This paper reviews the sample selection, DNA extraction, DNA enrichment and analysis approaches based on relevant research reports in recent years, aiming to promote the further development and improvement of the aged skeleton and teeth identification system.

Forensic Validation and Application Evaluation of IDentifier DNA Typing Kit (Yan-Huang34) / 法医学杂志

OBJECTIVES@#To investigate the technical performance of IDentifier DNA typing kit (YanHuang34) and evaluate its forensic application value.@*METHODS@#Following the Criterion of Forensic Science Human Fluorescence STR Multiplex Amplification Reagent (GB/T 37226-2018), IDentifier DNA typing kit (YanHuang34) was verified in 11 aspects of species specificity, veracity, sensibility, adaptability, inhibitor tolerance, consistency, balance, reaction condition verification, mixed samples, stability and inter batch consistency. The system efficiency of IDentifier DNA typing kit (YanHuang34) was compared with the PowerPlex® Fusion 6C System, VersaPlex® 27PY System and VeriFilerTM Plus PCR Amplification Kit. The IDentifier DNA typing kit (YanHuang34) was used to detect the swabs of biological samples in daily cases and the STR performances were observed.@*RESULTS@#IDentifier DNA typing kit (YanHuang34) had good species specificity, veracity, adaptability, inhibitor tolerance and balance. The sensibility was up to 0.062 5 ng. It was able to detect different types of samples, degraded samples and inhibitor mixed samples. Complete DNA typing could be obtained for samples with the mixture ratio less than 4∶1. The system efficiency of IDentifier DNA typing kit (YanHuang34) was very high, with TDP up to 1-1.08×10-37, CPEtrio and CPEduo up to 1-5.47×10-14 and 1-6.43×10-9, respectively. For the touched biological samples in actual cases, the effective detection rate was 21.05%. The system efficiency of kinship, single parent and full sibling identifications was effectively improved.@*CONCLUSIONS@#The IDentifier DNA typing kit (YanHuang34) is adaptive to the GB/T 37226-2018 requirements. It can be used for individual identification and paternity identification, and is suitable for application in the field of forensic science.

Establishment of Multiplex Amplification System of STR Loci in Felis Catus and Its Forensic Application / 法医学杂志

OBJECTIVES@#To construct a Felis catus STR loci multiplex amplification system and to evaluate its application value by testing the technical performance.@*METHODS@#The published Felis catus STR loci data were reviewed and analyzed to select the STR loci and sex identification loci that could be used for Felis catus individual identification and genetic identification. The fluorescent labeling primers were designed to construct the multiplex amplification system. The system was validated for sensitivity, accuracy, balance, stability, species specificity, tissue identity and mixture analysis, and investigated the genetic polymorphisms in 145 unrelated Felis catus samples.@*RESULTS@#Sixteen Felis catus autosomal STR loci and one sex determining region of Y (SRY) were successfully selected, and constructed a multiplex amplification system containing the above loci. The complete profile of all alleles could still be obtained when the amount of DNA template was as low as 0.25 ng. There was no specific amplification peak in other common animal samples. Population genetic surveys showed that total discrimination power (TDP) of the 16 STR loci was 1-3.57×10-20, the cumulative probability of exclusion (CPE) was 1-6.35×10-5 and the cumulative probability of matching was 3.61×10-20.@*CONCLUSIONS@#The Felis catus STR multiplex amplification system constructed in this study is highly sensitive, species-specific, and accurate in typing results, which can provide an effective solution for Felis catus species identification, individual identification and kinship identification in the field of forensic science.

Individual Identification in Facial Appearance Biometrics Based on Macroscopical Comparison / 法医学杂志

Individual identification is one of the research hotspots in the practice of forensic science, and the judgment is usually built on the comparison of the unique biological characteristics of the individual, such as fingerprints, iris and DNA. With the dramatic increase in the number of cases related to video image investigations, there is an increasing need for the technology to identify individuals based on the macroscopic comparison of facial appearance biometrics. At present, with the introduction of computer three-dimensional (3D) modeling and 3D superimposition comparison technology, considerable progress has been made in individual identification methods based on macroscopic comparison of facial appearance biometrics. This paper reviews individual facial appearance biometric methods based on macroscopical comparison, comprehensively analyzes the advantages and limitations of different methods, and puts forward recommendations and prospects for subsequent research.

Research Progress on the Application of Human Oral Microbiome in Forensic Individual Identification / 法医学杂志

The oral cavity is the second largest microbial bank in humans after the intestinal canal, colonizing a large number of microorganisms including viruses, bacteria, archaea, fungi and protozoa. The great number of microbial cells, good DNA stability, and individual has a unique microbial community, these characteristics make the human microbiome expected to become a new biomarker for forensic individual identification. This article describes the characteristics of human oral microorganisms and microbial molecular markers in detail, analyzes the potential application value of microorganisms in forensic individual identification, and reviews the research progress of human oral microorganisms in forensic individual identification.

New Advances, Challenges and Opportunities in Forensic Applications of Microbiomics / 法医学杂志

The succession of microbiota is closely associated with several essential factors, including race, sex, health condition, lifestyle, postmortem interval, etc., and it has great potential application value in forensic medicine. This paper summarizes recent studies on the forensic applications of the microbiome, including individual identification, geographical feature identification, origin identification of the tissue or body fluid, and postmortem interval estimation, and introduces the current machine learning algorithms for microbiology research based on next-generation sequencing data. In addition, the current problems facing forensic microbiomics such as the extraction and preservation of samples, construction of standardization and database, ethical review and practical applicability are discussed. Future multi-omics studies are expected to explore micro ecosystems from a comprehensive and dynamic perspective, to promote the development of forensic microbiomics application.

Research Progress of Exosomes and Their Forensic Significance / 法医学杂志

Exosomes are membranous tiny vesicles secreted by cells, which are widely found in the extracellular matrix and various body fluids and carry a variety of biologically functional molecules such as proteins, lipids, messenger RNA (mRNA) and microRNA (miRNA). Exosomes not only play important biological roles in the field of immunology and oncology, but also have potential application value in the field of forensic medicine. This article reviews the discovery, production and degeneration mechanism, biological functions, isolation and identification methods of exosomes, summarizes the research on exosomes and their significance in the field of forensic science, and discusses their applications in body fluid identification, individual identification, postmortem interval estimation to provide ideas for the application of exosomes in forensic work.

Research Progress on Individual Identification by Frontal Sinus Imaging / 法医学杂志

Frontal sinus imaging is an important research object in forensic individual identification due to the highly specific irregular air cavity shape of frontal sinus, the stability of its shape after maturity, and the wide clinical application of radiology technology. The use of frontal sinus imaging for individual identification has significance in the court. When the application of traditional individual identification methods such as fingerprint identification and DNA analysis are limited or cannot be effectively carried out, or when the corresponding dental records are lacking and in other special cases, individual identification with frontal sinus imaging comparison is an effective alternative. Various types of image data can be used for individual identification with frontal sinus, mainly based on artificial visual comparing. With limitations such as, high professional requirements, low efficiency and small application range, the methods cannot be used in mass disasters. In recent years, some computer image recognition techniques have been used in identification of frontal sinus imagings and can significantly improve the efficiency of recognition. Difficulties such as low manual recognition efficiency may be overcomed. This study summarizes the reports on forensic individual identification using frontal sinus imaging, to review the research progress on individual identification with frontal sinus imaging, to provide a reference for further research on frontal sinus imaging, and to provide ideas for exploration and establishment of a faster, more efficient and more accurate individual identification system.

Research Progress on Computer-Aided Skeleton-Based Individual Identification in Forensic Radiology / 法医学杂志

Individual identification based on imaging data of the skeleton of a corpse is a key technique for forensic identification. To reduce the influence of artificial factors, computer-aided semi-automatic or automatic individual identification has become one of the research directions of skeleton-based individual identification in forensic radiology. Therefore, this paper reviews and summarizes literatures related to estimation of anthropological information such as, age and sex by computer-aided forensic radiology bone characteristics and individual identification based on bone imaging characteristics, in order to provide reference on skeleton-based individual identification in forensic radiology.

The Region of Interest in Boundary Calibration for Palatal Ru-gae Image of Forensic Identification / 法医学杂志

Objective To examine the method of least-square fitting for calibrating the palatal rugae boundary. Methods According to the distribution of the teeth, the feature points were selected; when they were fit, the boundary of the palatal rugae area was created, thereby constructing a mask. The mask was used to remove the part located outside the boundary and filter out the interference. Three samples were utilized for the ex-periments and analyses to come. Results To evaluate the quantitative results of the fitting curves, the correla-tion coefficients(r)of the samples and the relationship between the actual mean value and ideal mean value was obtained through six fitting processes. The differences between the actual mean and ideal mean were found to be significantly small (from 0.2857 to 2.5000) in the six fitting processes, with the range of r close to 1(from 0.9896 to 0.9995). Conclusion The effect of the cubic polynomial fitting method adopted in this study was stable.The proposed boundary calibration method can effectively locate the palatal rugae boundary and remove the interference area, further promoting the practice of forensic identification.

Genetic Polymorphism and Forensic Application of 47 Autosomal InDel Loci in 5 Chinese Ethnic Groups / 法医学杂志

Objective To investigate the population genetic data of 47 autosomal insertion/deletion （InDel） polymorphism genetic markers involved in AGCU InDel 50 kit in Guangdong Han, Guangxi Zhuang, Guangxi Yao, Guangxi Jing, and Guangxi Mulam, and to evaluate their application in forensic DNA identification. Methods Multiplex amplification of the 768 unrelated individuals from the 5 ethnic groups mentioned above was performed with the AGCU InDel 50 kit. Genotyping was carried out by 3500xL gene analyzer, population genetic parameters were gathered and polymorphism analysis was performed. Results No linkage disequilibrium was found among 47 autosomal InDel loci in the 5 ethnic groups. The distribution of genotype frequency of 47 autosomal InDel loci confirmed to the Hardy-Weinberg equilibrium in Guangdong Han and Guangxi Zhuang. Except for rs139934789, the other 46 loci confirmed to the Hardy-Weinberg equilibrium in Guangxi Yao, Guangxi Jing, and Guangxi Mulam. The results of genetic variation analysis among the populations showed that 1.12% of genetic variation was caused by ethnic group differences. The cumulative discrimination power of 47 autosomal InDel loci for the 5 ethnic groups were all above 0.999 999 999 999 999. The cumulative probability of exclusion for each ethnic group was less than 0.999 9. The two Y-InDels were identified in all male individuals and were absent in all female individuals. Conclusion Except for rs139934789, the other 46 InDel loci have a relatively good genetic polymorphism in the 5 Chinese ethnic groups, and can be used for forensic individual identification and as effective supplements for paternity testing.

Sex Characteristics and Distribution of External Ear in Uygur Population of Xinjiang / 法医学杂志

Objective To analyze the characteristics of the bilateral external ears of Uygur adults by directly observing the morphological characteristics of the external ears of Uygur adults and classifying each feature. The frequency distribution of the characteristics was calculated to provide reference for forensic identification. Methods The 210 cases （75 males and 135 females） of bilateral external ear photos of Uygur adults in Xinjiang that met the inclusion criteria were collected. The frequencies of the features of the external ear were recorded and distinguished between the two sexes and the different sides. The data were statistically analyzed by SPSS 21.0 statistical software. Results The shapes of the external ears of males and females were commonly oblique or rectangular （34.67% of the left external ear of males and 41.33% of the right were oblique; 30.37% of the left and right external ear of females were rectangular）, while triangular ears were the rare variants and the least common. Sex and bilateral differences were observed as regards the form of the helix in the subjects. Normally rolled helix was the most common （58.67% males and 61.48% females for the left ear; 60.00% males and 72.59% females for the right ear）. Wide covering scapha helix was the most rare for the male left ear and flat helix was the most rare for the female right ear. Square and free earlobes were the most common （49.33% males and 62.96% females for the left ear; 40.00% males and 54.81% females for the right ear）, whereas triangular earlobes were rarely seen. Single knob tragus （40.00% males and 37.78% females for the left ear; 37.33% males and 33.33% females for the right ear） and projection type of Darwin's tubercle （50.67% males and 40.00% females for the left ear; 48.00% males and 39.26% females for the right ear） were found to be common. Conclusion The characteristics of the bilateral external ears of male and female Uygur adults have differences, which can be used for forensic identification.

Research Progress on Discrimination of Monozygotic Twins / 法医学杂志

Individual identification plays an import role in the practice of forensic medicine, and often provides crucial evidence for the analysis and detection of criminal cases.However, for individual identification in complex situations, such as monozygotic (MZ) twins assumed to be genetically identical, it is impossible to distinguish one from the other by using traditional forensic DNA typing system.Therefore, how to discriminate the MZ twins has become and will continue to be one of the difficult problems in forensic field.This paper summarized the genetic and epigenetic changes recently identified in MZ pairs, which might provide a new insight to forensic discrimination of MZ twins.

Genetic Parameters of SNP Loci in Next Generation Sequencing Kits and Their Comparison / 法医学杂志

OBJECTIVES@#To calculate genetic parameters of SNP loci in next generation sequencing kits, and to compare them with STR loci for establishing the conversion ratio between SNP and STR system effectiveness.@*METHODS@#Hardy-Weinberg equilibrium tests were performed in 101 SNP loci of next generation sequencing kits （ForenSeq™ DNA Signature Prep kit and Precision ID Identity Panel kit）. The parameters of system effectiveness of SNP loci in the cases of personal identification, trios, duos, and alleged parents were calculated, which were compared with the genetic parameters of STR loci.@*RESULTS@#Except 2 loci without the data of genotype frequency, other 99 SNP loci conformed to Hardy-Weinberg equilibrium tests （P>0.05）. In ForenSeq™ DNA Signature Prep kit, the CDP of 94 SNP loci was 1-1.152 1×10⁻³⁴, CPEtrio was 1-4.416 9×10⁻⁸, CPEduo was 1-8.483 7×10⁻⁵, and CPEAP was 1-1.222 7×10⁻¹². In Precision ID Identity kit, the CDP was 1-2.052 4×10⁻³³, CPEtrio was 1-8.709 3×10⁻⁸, CPEduo was 1-1.163 8×10⁻⁴, and CPEAP was 1-3.725 7×10⁻¹². In the cases of personal identification, trios, duos and alleged parents, the system effectiveness of 2.85, 4.51, 4.88 and 4.55 SNP loci was equal to that of 1 STR locus, respectively.@*CONCLUSIONS@#With high system effectiveness of SNP loci, the next generation sequencing kits is suitable for personal identification and paternity testing in forensic science.

The relationship between DNA methylation profile of peripheral blood and smoking / 中国法医学杂志

Objective To evaluate the potential application of separating smoking individuals from non-smoking ones by DNA methylation profiles from peripheral blood. Methods Human genome-wide DNA methylation data were downloaded from NIH GEOdata base. DNA methylation values from certain CpG sites were used to evaluate their significance between smokers and non-smokers by Student's T Test, as well as the clustering analysis. Results There are significant DNA methylation between smokers and non-smokers for certain CpGs. Conclusion Detection of methylation status from human peripheral blood can distinguish smokers from non-smokers.

The research of individual identify by comparison of auricle / 中国法医学杂志

Objective To study the characteristics of measurement points in auricle and to make a method of individual identification by auricle. To make an accurate, simple and reliable individual identification recognition to forensic anthropology by the auricle in the videos and pictures. Methods To select measurement points by the auricle pictures of the 148 adults of Han nationality -from 19 to 22 years old- beyond one month and to analysis the data by SPSS statistical software, analyzing the various factors that influence on the measurement result, then to calculate the ability of recognition, and to confirm the each index difference and the reference value range between the two batch of photos in the end. Results The 6 measurement points were retained by statistical test from the 10 measurement points. The result is stable, and the variation coefficient of each index is not quite different. Conclusion To confirm reference range of the 6 observation points so that to determine whether the two auricle pictures belong to the same individual is accurate and feasible method.