[Contrast-enhanced ultrasound manifestations of IgG4 related autoimmune pancreatitis].

To analyze and summarize the contrast-enhanced ultrasound (CEUS) characteristics in patients with IgG4 related autoimmune pancreatitis (IgG4-AIP). A total of 54 patients (aged 26 to 76 years old) with IgG4-AIP were collected and retrospectively analyzed. The results demonstrated that there is a variety of enhanced performance on CEUS in patients with IgG4-AIP in the early stage, for some them, especially for those with mass-type pancreatitis, their sonographic appearance and the CEUS characteristics are similar when compared with the patients with pancreatic carcinoma, with varying degrees of low enhancement in the arterial phase, venous phase and delayed stage. Therefore, it is not advisable to make a differential diagnosis based on CEUS alone, and comprehensive evaluation is warranted.

Mitochondrial DNA Polymorphism in Zhejiang She Population Based on Next Generation Sequencing.

ABSTRACT: Objective To study the genetic polymorphism of whole mitochondrial DNA （mtDNA） genomes in She population in Zhejiang and to explore the maternal genetic structure of the She population. Methods Whole mtDNA genomes of 231 unrelated individuals from She population in Zhejiang Province were sequenced. The number of mutations and population genetics parameters such as, the haplotype diversity （HD）, discrimination power （DP）, and random match probabilities （RMP） were analyzed. The mtDNA haplogroups of Zhejiang She population were classified, and the maternal genetic relationships between She and nine other Chinese populations were estimated. Results In 231 Zhejiang She samples, 8 507 mutations （702 types） were observed and the samples were classified into 94 haplogroups. The HD, DP and RMP values were 0.998 6, 0.994 2 and 0.005 8, respectively. The lowest genetic differentiation degree （Fst=0.006 89） was detected between Zhejiang She population and southern Han population. Principal component analysis （PCA） and median-joining network analysis showed that the genetic distance of Zhejiang She population with Guangxi Yao, Yunnan Dai and Southern Han populations was relatively close, but the population still had some unique genetic characteristics. Conclusion The whole mtDNA genomes are highly polymorphic in Zhejiang She population. The Zhejiang She population contains complex and diverse genetic components and has a relatively close maternal genetic relationship with Guangxi Yao, Yunnan Dai and Southern Han populations. Meanwhile, Zhejiang She population has kept its unique maternal genetic components.

Identification of Cannabis Sativa L. Based on rbcL Sequence.

ABSTRACT: Objective To assess the feasibility of the rbcL sequence of chloroplast DNA as a genetic marker to identify Cannabis sativa L. Methods The rbcL sequences in 62 Cannabis sativa L. samples, 10 Humulus lupulus samples and 10 Humulus scandens DNA samples were detected, and 96 rbcL sequences of the Cannabaceae family were downloaded from Genbank. Sequence alignment was performed by MEGA X software, the intraspecific and interspecific Kimura-2-Parameter （K2P） genetic distances were calculated, and the system clustering tree was constructed. Results The rbcL sequence length acquired by sequencing of Cannabis sativa L. and Humulus scandens were 617 bp and 649 bp, respectively, and two haplotypes of Cannabis sativa L. were observed in the samples. The BLAST similarity search results showed that the highest similarity between the sequences acquired by sequencing and Cannabis sativa L. rbcL sequences available from Genbank was 100%. The genetic distance analysis showed that the maximum intraspecific genetic distance （0.004 9） of Cannabis sativa L. was less than the minimum interspecific genetic distance （0.012 9）. The results of median-joining network and system clustering tree analysis showed that Cannabis sativa L. and other members of the Cannabaceae family were located in different branches. Conclusion The rbcL sequence could be used as a DNA barcode for identifying Cannabis sativa L., and combined with comparative analysis of the rbcL sequence and system cluster analysis could be a reliable and effective detection method for Cannabis sativa L. identification in forensic investigation.

Forensic Application of Next Generation Sequencing Technology in the Typing of Y Chromosome Genetic Markers.

ABSTRACT: The paternal inheritance characteristics of Y chromosome have been widely used in the forensic genetics field to detect the genetic markers in the non-recombining block, and used in the studies such as, genetic relationship identification, mixed stain detection, pedigree screen and ethnicity determination. At present, capillary electrophoresis is still the most common detection technology. The commercial detection kits and data analysis and processing system based on this technology are very mature. However, the disadvantages of traditional detection technology have gradually appeared with the rapid growth of bio-information amount, which promotes the renewal of forensic DNA typing technology. In recent years, next generation sequencing （NGS） technology has developed rapidly. This technology has been applied to various fields including forensic genetics and has provided new techniques for the detection of Y chromosome genetic markers. This article describes the current situation and application prospects of the NGS technology in forensic Y chromosome genetic markers detection in order to provide new ideas for future judicial practice.

Progress on Copy Number Variation and Its Application in Forensic Medicine.

ABSTRACT: Recently, researches on copy number variation （CNV） have extended to every field, such as etiological exploration and precise treatment of complex diseases, as well as genetic breeding and evolution. The unique genetic characteristics of CNV have made people gradually believe that it could be used as a biological genetic marker to solve related problems. With the development of detection technology, application of CNV in forensic medicine will increase gradually. In this paper, the concept and development of CNV, as well as its application in forensic medicine are summarized, to provide new ideas for the practical application of CNV in the future.

Research Progress on Age Estimation Based on DNA Methylation.

ABSTRACT: Age estimation is of great significance in the fields of criminal investigation and forensic identification. It can provide the age information of individuals to judicial departments to facilitate the development of judicial work. In recent years, age estimation methods expanded from the morphological level to the molecular biology level. With the rapid development of epigenetics represented by DNA methylation, and the advancement of DNA methylation detection technology together with the detection platform, many age estimation methods based on DNA methylation biomarkers, or using several biological fluids, such as blood, blood stains, saliva, semen stains, etc. are developed. Currently, researches related to age estimation based on DNA methylation are relatively widely carried out. This paper summarizes the researches on age estimation based on DNA methylation, in order to provide references for related studies and forensic applications.

Evaluation and Countermeasures of the Implementation of Forensic Clinical Identification Standards Based on the Perspective of Accreditation.

ABSTRACT: The new Standardization Law, implemented in 2018, has added a standard post-implementation evaluation system, aiming to continuously improve the quality of standards through post-implementation evaluation. Standards in the forensic science field are closely related to accreditation activities. Forensic science standards are not only the criteria on which accreditation activities are carried out, but also one of the key contents of the inspection of forensic science institutions in accreditation activities. Since 2018, the certification and accreditation policies in the forensic science field have also been changed, which has brought impacts on the construction of a standard system based on accreditation.This paper analyzes the standard data from China National Accreditation Center from Conformity Assessment on forensic clinical identification accreditation assessment. It points out that the current coverage of laboratory accreditation activities is limited, the development in different provinces is unbalanced, and there is overlap and crossover in the standards in use. It is emphasized that the construction of the national forensic science standardization technical committee, the improvement of the forensic science standard system, the establishment of the standard implementation evaluation index system, and promotion of the coordination of standards, and the certifications and accreditations should be accelerated, in order to continue to promote the standardization and accreditation activities in the field of forensic science.

Application of Multiple Genetic Markers in Determination of Full and Half Sibling Relationship： A Case Report.

ABSTRACT: Objective To investigate the application of the comprehensive use of multiple genetic markers in full and half sibling relationship testing through the identification of a case of suspected sibling relationship. Methods Genomic DNA were extracted from bloodstain samples from 4 subjects （ZHANG-1, ZHANG-2, male; ZHANG-3, ZHANG-4, female）. Autosomal STR loci, X-STR, Y-STR loci and polymorphisms of mtDNA HV-Ⅰ and Ⅱwere genotyped by EX20 STR kit, X19 kit, Data Y24 STR kit, and Sanger sequencing, respectively. Results According to autosomal STR based IBS scoring results, full sibling relationships were indicated among ZHANG-2, ZHANG-3 and ZHANG-4, but those were not indicated between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4. According to autosomal STR based FSI and HSI, with ITO method and discriminant function method, full sibling relationships among ZHANG-2, ZHANG-3 and ZHANG-4 were indicated, and half sibling relationships between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4 were also indicated. X-STR and mtDNA sequencing results showed that all the 4 samples came from a same maternal line, and Y-STR results showed that ZHANG-1 and ZHANG-2 did not come from a same paternal line, which supported the half sibling relationship between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4, verified by parental genotype reconstruction based on autosomal STR genotyping. Conclusion For the identification of sibling relationships, it is effective to have reliable results with the mutual verification and support of multiple genetic markers （autosomal STR, sex chromosomal STR and mtDNA sequence） and calculations （IBS, ITO, discriminant function method and family reconstruction）.

Evaluating the Efficiency of REPLI-g® Single Cell Kit for Trace DNA Amplification.

ABSTRACT: Objective To evaluate the efficiency of REPLI-g® Single Cell Kit for sample DNA amplification, and explore its application value in forensic trace DNA amplification. Methods Three DNA extraction kits were selected to extract DNA from peripheral blood of 10 unrelated individuals. The DNA yield and purity of the three DNA extraction kits were compared. According to the results of comparison, one DNA sample was selected to concentrate and dilute, then used as the initial sample of whole genome amplification （WGA）. REPLI-g® Single Cell Kit was used to amplify the initial sample at the whole genome level. The amplification yield and amplification times were calculated, and the distribution of DNA fragments was detected by agarose gel electrophoresis. Goldeneye® DNA ID System 20A Kit was used to perform the STR typing of the initial sample and DNA samples amplified at the whole genome level to evaluate the performance of REPLI-g® Single Cell Kit in trace DNA amplication in terms of purity and yield as well as the success rate of STR typing. Results After comparison, one DNA sample was selected from QIAsymphony® DNA Investigator® Kit extracts to concentrate and dilute as the initial sample of WGA. After amplifying the whole genome of a series of initial samples by REPLI-g® Single Cell Kit, the lowest average of amplification yield reached 8.77×103 ng, while the average of the corresponding amplification times reached 1.40×106. DNA fragments were large and concentrated. The STR typing success rate of WGA samples became lower with the decrease of initial samples used, but when the amount of samples was lower than 0.5 ng, the STR typing success rate of samples after DNA WGA was higher than that of samples without DNA WGA. Conclusion REPLI-g® Single Cell Kit can increase the yield of template DNA. Especially for trace DNA, the STR typing success rate can be improved to a certain extent.

Analysis of Forensic Sciences Literature in SCIE from 2008 to 2017.

OBJECTIVES: To analyze the literature on forensic sciences indexed in Science Citation Index Expanded （SCIE） in recent 10 years, and to understand the research status, characteristics and trends in the field of forensic sciences. METHODS: Literature on forensic sciences from 2008 to 2017 in Web of Science （WoS） was retrieved. The documents number and geographical distribution, document types, source titles, organizations, research areas, authors, funding agencies, and the high cited articles were detected. The impact factors （IF） of journals were retrieved in Journal Citation Reports （JCR）. The data were analyzed with descriptive statistics. RESULTS: From 2008 to 2017, there were 21 001 documents on forensic sciences in SCIE. The main document type was articles, with English as the major language. With regards to research areas, pathology has the largest number of papers worldwide, and genetics and heredity has the largest number of publications in mainland China. Among the 18 journals where the documents was published, Forensic Science International ranks the first on publication count, and Forensic Science International Genetics has the highest IF （5.637） in the JCR 2017. In 2017, the number of papers from mainland China increased by 48.50% compared with 2016, which was higher than the global increase （32.63%） and the top-5 countries in terms of number of publications （the US, Germany, the UK, Australia, Italy）. The average document count per organization is 1.98 worldwide and 1.17 in mainland China, respectively. The publication number per author is 0.53 worldwide and 0.36 in mainland China, respectively. Around 28.17% of the publications were funded, with National Natural Science Foundation of China （NSFC） as the Top 1 funding agency （192 papers）. Among the documents with citations, the most cited publication has been cited for 366 times. CONCLUSIONS: The yearly numbers of publications on forensic sciences are increasing during recent 10 years. Focusing on the mainland China, there would be more high-quality papers with the steady funding of NSFC.

Formula Derivation for the Probability Distribution of IBS Score in Unrelated Individual Pairs.

OBJECTIVES: To derive the probability equation given by STR allele frequencies of identity by state （IBS） score shared by unrelated individual pairs. METHODS: By comparing the STR genotypes of two unrelated individuals, three mutually exclusive combinations could be obtained： （1） sharing 2 identical alleles, a2=1, otherwise a2=0; （2） sharing 1 identical allele, a1=1, otherwise a1=0; （3） sharing 0 identical allele, a0=1, otherwise a0=0. And the IBS score of the one STR locus in this unrelated individual pair could be given by the formula： ibs=2a2+a1. The probability of a2=1 （p2）, a1=1 （p1） and a0=1 （p0） were derived and expressed in powers of the allele frequencies. Subsequently, for a genotyping system including n independent STR loci, the characteristics of binomial distribution of IBS score shared by a pair of unrelated individuals could be given by p2l and p1l （l=1, 2, …, n）. RESULTS: All the general equations of p2, p1 and p0 were derived from the basic conceptions of a2, a1 and a0, respectively. Given fi （i=1, 2, …, m） as the ith allele frequency of a STR locus, the general equations of p2, p1 and p0 could be respectively expressed in powers of fi： [Formula: see text],[Formula: see text] and [Formula: see text]. The sum of p2, p1 and p0 must be equal to 1. Then, the binomial distribution of IBS score shared by unrelated individual pairs genotyped with n independently STR loci could be written by： IBS~B（2n, π）, and the general probability, π, could be given by the formula： [Formula: see text]. CONCLUSIONS: In the biological full sibling identification, the probability of null hypothesis corresponding to any specific IBS score can be directly calculated by the general equations presented in this study, which is the basement of the evidence explanation.

Research Progress on InDel Genetic Marker in Forensic Science.

Genetic markers in forensic DNA typing experienced the variable number of tandem repeats （VNTR） sequences and the short tandem repeats （STR） sequences. With the emerge of sequencing technology, the third generation of genetic markers were found out, which usually have two alleles including single nucleotide polymorphism （SNP） and insertion/deletion （InDel）, also known as biallelic genetic markers. Because of the insertions or deletions of DNA fragments, InDel genetic marker reveals DNA fragment length polymorphism and widely distributes across the whole genome. InDel genetic marker is numerous and has the characteristics of STR and SNP genetic markers, which has been applied in the fields of genetics and anthropology. This review focuses on the research progress of InDel genetic marker in forensic science, aiming to review and summarize the main research findings in recent years and provide clues for future researches.

[Assessment on Application of 24 Y-STR Loci in Forensic Science].

OBJECTIVES: To select a Y-STR marker system with strong haplotype identification ability, appropriate mutation rate and high compatibility and to assess its forensic application. METHODS: The 24 Y-STR loci were tested by self-built fluorescent multiplex system, and the forensic assessment was conducted by 139 pairs of father-son samples collected in Jinan, Shandong province. RESULTS: Totally 176 alleles were identified among the 24 Y-STR loci in the sample of 139 unrelated individuals labeled with father, and the gene diversity （GD） distributed between 0.083 7 （DYS645）-0.966 9 （DYS385a/b）. According to the 24 Y-STR loci, 139 different haplotypes were detected from 139 unrelated male individuals labeled with father in Han population of Shandong province and with no shared haplotype observed. The overall haplotype diversity （HD） was 1 and the discrimination capacity （DC） was 1. A total of 5 one-step mutations events were observed among the 24 Y-STR loci in 139 pairs of father-son. The average mutation rate was 0.001 5 [95% CI （0.000 5, 0.003 5）]. CONCLUSIONS: The system of 24 Y-STR loci shows a strong individual recognition ability and low mutation rate in the population in Jinan, Shandong province, and it has good application value in forensic science.

[Forensic Application of SiFaSTR™ 23plex DNA ID System in Han Population of Eastern China].

OBJECTIVES: To investigate the genetic polymorphism of 21 autosomal STR loci and DYS391 locus of SiFaSTR™ 23plex DNA ID system in Han population of eastern China and to evaluate its application value in forensic science. METHODS: Typing test of 2 000 unrelated individuals was performed using SiFaSTR™ 23plex DNA ID system. The population genetic parameters of STR loci were statistically analysed. A total of 3 198 parentage confirmed cases were detected with that system and the mutation conditions were observed in 21 autosomal STR loci. RESULTS: All the 21 autosomal STR loci showed no significant departure from Hardy-Weinberg equilibrium （P>0.05）. The Ho ranged from 0.617 5 to 0.927 0. The DP ranged from 0.796 4 to 0.986 9, as well as the PIC distributed from 0.561 1 to 0.912 3. The CDP was 0.999 999 999 999 999. The CPEduo was 0.999 997 431 701 961, while CPEtrio was 0.999 999 999 654 865. Five alleles were detected in DYS391 locus, with the allele frequency from 0.004 0 to 0.729 0, and GD was 0.418 9. Except D13S317 and D10S1248, seventy-six mutation events were observed at the rest nineteen autosomal STR loci. Among them, seventy-five （98.68%） were one step mutation, and only one （1.32%） was three steps mutation. The mutation rate ranged from 0.246 5×10⁻³ to 2.711 4×10⁻³, and the averaged mutation rate was 0.892 1×10⁻³ （95% CI： 0.70×10⁻³-1.10×10⁻³ï¼‰. In 33 trio mutation cases, the proportion of the paternal mutation and the maternal mutation was 2.09:1. CONCLUSIONS: The involved STRs are highly polymorphic in Eastern Han population with acceptable mutation rates by the SiFaSTR™ 23plex DNA ID system, which is suitable for paternity testing and individual identification.

Research Progress on Discrimination of Monozygotic Twins.

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.

Co-aggregation of major psychiatric disorders in individuals with first-degree relatives with schizophrenia: a nationwide population-based study.

A previous genetic study has suggested that schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) share common disease-associated genes. However, whether individuals with first-degree relatives (FDRs) with schizophrenia have a higher risk of these major psychiatric disorders requires further investigation. This study used Taiwan's National Health Insurance Research Database and identified 151 650 patients with schizophrenia and 227 967 individuals with FDRs with schizophrenia. The relative risks (RRs) of schizophrenia and other major psychiatric disorders were assessed in individuals with FDRs with schizophrenia. The individuals with FDRs with schizophrenia exhibited higher RRs (95% confidence interval) of major psychiatric disorders, namely schizophrenia (4.76, 4.65-4.88), bipolar disorder (3.23, 3.12-3.35), major depressive disorder (2.05, 2.00-2.10), ASD (2.55, 2.35-2.77) and ADHD (1.31, 1.25-1.37) than were found in the total population. Several sensitivity analyses were conducted to confirm these results. A dose-dependent relationship was observed between the risks of major psychiatric disorders and the numbers of FDRs with schizophrenia. The increased risks of major psychiatric disorders were consistent in different family relationships, namely among parents, offspring, siblings and twins. Our study supports the familial dose-dependent co-aggregation of schizophrenia, bipolar disorder, major depressive disorder, ASD and ADHD, and our results may prompt governmental public health departments and psychiatrists to focus on the mental health of individuals with FDRs with schizophrenia.

[Full Sibling Identification by IBS Scoring Method and Establishment of the Query Table of Its Critical Value].

OBJECTIVES: To establish a query table of IBS critical value and identification power for the detection systems with different numbers of STR loci under different false judgment standards. METHODS: Samples of 267 pairs of full siblings and 360 pairs of unrelated individuals were collected and 19 autosomal STR loci were genotyped by Goldeneye™ 20A system. The full siblings were determined using IBS scoring method according to the 'Regulation for biological full sibling testing'. The critical values and identification power for the detection systems with different numbers of STR loci under different false judgment standards were calculated by theoretical methods. RESULTS: According to the formal IBS scoring criteria, the identification power of full siblings and unrelated individuals was 0.764 0 and the rate of false judgment was 0. The results of theoretical calculation were consistent with that of sample observation. The query table of IBS critical value for identification of full sibling detection systems with different numbers of STR loci was successfully established. CONCLUSIONS: The IBS scoring method defined by the regulation has high detection efficiency and low false judgment rate, which provides a relatively conservative result. The query table of IBS critical value for identification of full sibling detection systems with different numbers of STR loci provides an important reference data for the result judgment of full sibling testing and owns a considerable practical value.

Analysis of the 19 Y-STR and 16 X-STR loci system in the Han population of Shandong province, China.

The sex-linked short tandem repeats (STR), Y-STR and X-STR, are important for autosomal STRs in forensic paternity testing. We evaluated the forensic parameters of 19 Y-STRs and 16 X-STRs in the Han population of Shandong province, China. A Goldeneye 20Y kit (DYS391, DYS389I, DYS390, DYS389II, DYS348, DYS456, Y-GATA-H4, DYS447, DYS19, DYS392, DYS393, DYS388, DYS439, DYS635, DYS448, DYS460, DYS458, DYS437, DYS385 a/b) was used to analyze the forensic parameters of 534 unrelated males. A Goldeneye17X system (DXS6795, DXS9902, DXS8378, HPRTB, GATA165B12, DXS7132, DXS7424, DXS6807, DXS6803, GATA172D05, DXS6800, DXS10134, GATA31E08, DXS10159, DXS6789, DXS6810, amelogenin) was used to analyze 97 unrelated males and 214 females. In addition, we used the kits to examine 5 cases with abnormal amelogenin test results, as well as a male child with agenosomia typed by autosomal STR. We found 203 Y-STR haplotypes with allele frequencies ranging from 0.0019 to 0.7959, and GD ranging from 0.3429 to 0.9667. Expect in DXS6803, the allele frequencies of the other 15 X-STR loci showed no differences between females and males. PDF ranged from 0.5504 to 0.9638, while PDM ranged from 0.3176 to 0.8377. With the exception of DXS6803 and DXS6810, the allele frequencies of other X-STR loci were in accordance with Hardy-Weinberg equilibrium in females. One amelogenin negative case was characterized as a deletion of Y-DYS458. This paper provided data regarding the genetic polymorphism of Y-STRs and X-STRs in the Han population, and demonstrated the importance of Y-STR and X-STR in forensic autosomal STR analysis.