Examining a greater number of short tandem repeats (STRs) is essential for cases involving mutations, consanguinity, and complex kinship testing. However, previous population studies were mostly limited to fewer than 40 STRs. Therefore, this study investigated the genetic polymorphism, linkage disequilibrium, and mutation rates of 81 autosomal STR loci in the Han Chinese population of northern China. We confirmed the core repeat structure of STR loci, and focused on evaluating the forensic application value of the Category C and 21 additional STR loci not included in the standard "Forensic science-Data structures of selected loci from the DNA database" (GB/T 41009-2021). Blood samples from 400 unrelated healthy Northern Han Chinese individuals and parent-child blood samples from 157 families were detected using GSTAR TM25, GSTAR TM31FS, and GSTAR TM29HS kits. Genetic analysis was performed on genotyping data of 81 autosomal STR loci. The core sequence structures of newly added 15 STR loci were confirmed by sequencing the allelic ladder. After applying Bonferroni correction, all 81 autosomal STR loci conformed to Hardy-Weinberg equilibrium. The observed heterozygosity ranged from 0.4375 to 0.9075, discrimination power from 0.6332 to 0.9845 (lowest at LPL), polymorphism information content from 0.3938 to 0.9092, probability of exclusion for trios from 0.1384 to 0.8108, and for duos from 0.0955 to 0.7069. Significantly, linkage disequilibrium was observed between D5S2500 and D5S2800 loci. When excluding the D5S2800 locus, the cumulative discrimination power (CDP) of remaining 80 autosomal STR loci was 1-2.293×10-89, cumulative probability of exclusion (CPE) of trios was 1-5.074×10-31, and cumulative exclusion probability of duos was 1-1.400×10-19. A total of 13 mutations were observed across 508 meiotic events in 157 families at 10 STR loci. The mutation rates for D5S818, D11S2368 and D18S51 were 0.004, while those of D6S1043, D7S1517, D11S4463, D13S325, D14S1434, D20S482 and D20S85 were 0.002. In conclusion, the 81 genetic loci, including Category C and newly added STRs, exhibit good or moderate polymorphism and are suitable for individual identification, paternity testing, and kinship identification. Given the linkage disequilibrium between the D5S2500 and D5S2800, if simultaneous on the capillary electrophoresis platform, it is recommended to use only the test results from the D5S2500 locus for statistical analysis. This data generated provide allele frequency and mutation rate for a large number of STRs, along with the clarified core sequences, thus offering an important data foundation for DNA evidence evaluation.

Y chromosome short tandem repeat (Y-STR) is an important genetic marker in forensic practices. Length-based Y-STR genotyping method has been used to screen paternal lineages and successfully solved many serious cases. However, it is hard to discriminate paternal lineages with similar or identical length-based Y-STR genotypes. Next-generation sequencing-based Y-STR genotyping method could be used to solve the problem, and already be applied to criminal scene investigations. Nevertheless, previously studied data were inadequate and scattered, and sequence features of Y-STR loci were insufficiently summarized, which hindered the deep forensic application of Y-STR loci. Here, we review the sequence features of repeat and flanking regions on 41 widely used forensic Y-STR loci based on public literature data. Furthermore, we identify haplogroup-associated Y chromosome single nucleotide polymorphisms within these regions and explore potential applications of sequence-based polymorphisms. This review is expected to serve as a valuable reference for paternal lineage discrimination and paternal biogeographic ancestry inference using Y-STR sequence features.

Background The external human ear is a polymorphic and polygenic structure with individual uniqueness, making it a valuable target in forensic DNA phenotyping (FDP) studies. Previous genome-wide association studies have identified multiple genetic loci associated with variation in ear characteristics. However, research focused on predicting ear morphology within the context of FDP remains limited. This study aimed to develop DNA-based predictive models for external ear morphology in the Chinese population. Methods Digital photographs of 675 volunteers were used to score 13 ear phenotypes, each categorized into three levels. Multinomial logistic regression (MLR) was applied for genetic association analysis. Five predictive models—MLR, support vector machines, random forest, AdaBoost, and k-nearest neighbors—were developed and evaluated using 10-fold cross-validation. Results Genetic association analysis identified several influential single-nucleotide polymorphism (SNPs) for each ear phenotype. Among the five models, AdaBoost and MLR demonstrated superior performance, achieving area under the curve (AUC) values above 0.7 for predicting absent tragus cases (level_0). To simplify classification, binary models incorporating genetic interactions were constructed for absent tragus cases. Specifically, the AdaBoost model achieved an AUC of 0.74, while the binary logistic regression (BLR) model reached an AUC of 0.72. Conclusions These findings highlight the potential forensic application of genetic markers in predicting ear morphology within the Chinese population, contributing to the advancement of FDP research and practice.

Formalin-fixed tissues possess irreplaceable value as a source of DNA for identification, especially when fresh samples are unavailable. Nonetheless, extracting and amplifying DNA from these tissues is challenging, primarily due to formaldehyde-induced cross-linking and nucleic acid fragmentation. In this study, two pre-extraction treatments, gradual dehydration using ethanol and pre-digestion heat treatments, and three DNA extraction methods, the Chelex-100 method, TIANamp FFPE DNA Kit, and ML Ultra-micro DNA extraction kit, were utilized to optimize DNA extraction from different tissues, which were fixed in 4

Objective Our study aimed to provide a comprehensive overview of the current status and dynamic trends of the human immunodeficiency virus(HIV) prevalence in Sichuan, the second most heavily affected province in China, and to explore future interventions.Methods The epidemiological, behavioral, and population census data from multiple sources were analyzed to extract inputs for an acquired immunodeficiency syndrome(AIDS) epidemic model(AEM).Baseline curves, derived from historical trends in HIV prevalence, were used, and the AEM was employed to examine future intervention scenarios.Results In 2015, the modeled data suggested an adult HIV prevalence of 0.191% in Sichuan, with an estimated 128,766 people living with HIV/AIDS and 16,983 individuals with newly diagnosed infections.Considering current high-risk behaviors, the model predicts an increase in the adult prevalence to0.306% by 2025, projecting an estimated 212,168 people living with HIV/AIDS and 16,555 individuals with newly diagnosed infections.Conclusion Heterosexual transmission will likely emerge as the primary mode of AIDS transmission in Sichuan. Furthermore, we anticipate a stabilization in the incidence of AIDS with a concurrent increase in prevalence. Implementing comprehensive intervention measures aimed at high-risk groups could effectively alleviate the spread of AIDS in Sichuan.

X-chromosomal genetic markers are frequently employed in forensic parentage determination owing to their distinctive inheritance patterns. The kinship analysis revealed that two sisters who were not identical twins had identical genotypes on the X chromosome, encompassing 36 X-chromosomal short tandem repeats (X-STRs) and 29 X-chromosomal single-nucleotide polymorphisms (X-SNPs) that spanned the whole X chromosome from the p-telomere to the q-telomere. The identical X-STRs and X-SNPs in the daughters could be the result of linkage or a rare chance of occurrence. This highlights the need for careful analysis and interpretation when dealing with X chromosome markers and that in individual cases, even if two women share an allele at each locus, this does not necessarily mean that they are paternal sisters. The likelihood of random concordance due to maternal alleles must be taken into account.

A six-color fluorescent multiplex amplification system for 31 Y-chromosomal short tandem repeats (Y-STRs) (DYS19, DYS390, DYS391, DYF399S1, DYF404S1, DYS439, DYS444, DYS449, DYS452, DYS456, DYS458, DYS460, DYS481, DYS508, DYS513, DYS516, DYS518, DYS543, DYS547, DYS549, DYS552, DYS557, DYS570, DYS576, DYS612, DYS622, DYS626, DYS627, DYS630, DYS635, and Y-GATA-A10) was developed for investigating the mutation rates of 31 highly mutated Y-STR genes in the Han population of northern China. The mutation rates of the 31 highly mutated Y-STRs were calculated using the father–son pair study method after typing 526 Northern Han father–son pairs with this system. Statistically, 148 Y-STR mutations were found, with mutation rates ranging from 0 (95% confidence interval [CI] 0 to 9.0 × 10−3, DYS622) to 7.0 × 10−2 (95% CI 5.1 × 10−2 to 9.7 × 10−2, DYF399S1). Out of these, 126 father–son pairs were successfully identified, with a distinction rate of 24.0% (95% CI 20.4%–27.9%). The ability of the 31 highly mutated Y-STRs to distinguish closely related males from the same paternal lineage in the Northern Han population is extremely valuable for criminal investigations and other purposes.

Objective: To investigate 38 Y-chromosome short tandem repeat (Y-STR) genetic polymorphisms in Beijing Han and analyze the genetic distance with neighboring or linguistically similar populations. Materials and Methods: In the study, we selected 531 unrelated male individuals of Beijing Han, and the results were statistically analyzed by testing with GSTAR™ 41Y reagents. Results: The allele peak heights were balanced among the Y loci, the amplified fragment ranged from 100 to 500 bps. A total of 531 haplotypes were detected in 531 samples. Eight null genotypes were observed on locus DYS448. One and three double alleles were observed on single-copy locus DYS576 and DYS19, respectively. DYS385 a/b, DYF387S1 a/b, and DYS527 a/b were more common in double copies, but 3, 13, and 11 triple alleles were detected, respectively. The gene diversity values of Y-STRs except DYS391, DYS438, and DYS645 were >0.5. Twenty-seven Y-STRs of Beijing Han population were selected for genetic distance comparison with 17 populations including Changchun Han, with Rst values ranging from 0.0002 to 0.1703. Conclusion: The 38 Y-STRs in this study have strong male lineage identification ability and have great potential for individual identification, kinship identification, Y-STR database construction, and genetic relationship research.

Rana hanluica is an endemic amphibian in China that is distributed in the hills and mountains south of the Yangtze River. In this study, 162 samples (comprising six groups) from 19 localities were collected, and the genetic diversity of R. hanluica groups was studied using mitochondrial cytb and nuclear rag2. The results showed that the genetic diversity of R. hanluica groups as a whole is high in haplotype diversity and low in nucleotide diversity. All haplotypes clustered into one branch and showed inconsistencies with the geographic structure. The levels of gene flow between the NL group and the other five groups as well as between the LXS group and two groups (WYS and NL) were all greater than 1, indicating that there was no barrier to gene flow between the above groups. Analysis of molecular variance also showed that genetic variation primarily occurred within groups, but the higher genetic differentiation reflected differentiation between groups of R. hanluica that may have been caused by genetic drift. Among the six groups of R. hanluica , only the LXS and NL groups have expanded. In conclusion, the degree of genetic diversity in each group of R. hanluica was not very high, while the level of genetic diversity varied significantly among groups. It is recommended that priority should be given to protecting groups with a large number of unique haplotypes (e.g., NL and LXS); the NL group is distributed in the South Ridge, as an important biological corridor.

与广义证据科学相比,狭义证据科学是指综合运用自然科学和社会科学的理论与方法,研究与案件事实认定有关的证据采集、科学鉴定、证据规则、证据解释与评价等一般规律的新兴交叉学科.其研究范围包括证据法学、法庭科学(法医学、物证技术学)、科学证据学、证据科学方法论等领域.证据科学交叉学科建设有助于应对事实认定科学化的挑战,可以为当代法律人才培养提供必备的科学知识,为法治国家司法文明建设奠定理性基础,也可为国家安全与和谐社会建设提供智力支持.本研究报告论述了狭义证据科学的概念、国内外研究现状、研究前沿与重大科学问题及发展规划,提出了建设独立的证据科学学科的一系列政策建议.

1 案例资料 1.1 案情 在一起遗产继承纠纷案件中,需要确定李某(女)的身份,但可疑父王某强已去世,留有一婚生女王某,故办案单位委托我所对李某与王某是否为同父异母的半同胞姐妹进行鉴定.经调查,王某的生母毛某、李某的生母周某以及王某的祖母赵某均在世,故要求她们配合参与本案鉴定.

美国法庭科学领域的标准制定工作从私人组织发展而来,标准来源较为分散,后经联邦政府的法庭科学标准化管理而趋于统一,经过了由分散走向集中的管理模式且卓有成效.其早期发展与目前我国法庭科学标准化工作所面临的不协调的现状存在一定的相似性.本文着重于介绍美国的科学领域全体委员会(OSAC)模式并分析了该标准化管理工作对于我国法庭科学标准化工作发展的启示.

[目的]调查31个X-STR基因座在中国北方汉族的遗传多态性、连锁不平衡情况和突变率.[方法]采集209个中国北方汉族健康志愿者家系样本,用MicroreaderTM 19X和AGCU X19 STR荧光检测试剂盒检测,统计基因座的突变率.选取家系中父亲或母亲各207个样本,组成男性和女性无关个体组并进行遗传多态性研究和连锁不平衡检验.[结果]共检出344个等位基因,基因频率分布在0.001 6-0.810 0之间.其中多态性信息含量最丰富的基因座是DXS10135(PIC=0.912 4).个体识别能力在男、女群体中分别为0.330 5-0.918 1、0.534 0-0.987 6.累积个人识别概率在男、女群体中分别为1-4.566 4×10-19、1-1.578 4×10-31.平均排除概率在三联体和二联体中分别为0.312 7-0.912 4、0.193 5-0.844 6.累积平均排除概率在三联体和二联体中分别为1-2.281 9×10-17、1-2.509 0×10-12.经分析,有1对X-STR(DXS10103-DXS10101)存在明显连锁不平衡现象.在414次减数分裂中观察到19个X-STR基因座有突变,平均突变率为0.002 3,突变率最高的基因座是DXS10135,为0.012 1.[结论]获得的31个X-STR遗传学数据为法医学鉴定提供了基础数据.DXS10103-DXS10101存在连锁不平衡,在应用时需按照单倍型频率分析.应用高突变率基因座时需保持谨慎,不要因为个别基因座不符合遗传规律而排除具有某种亲缘关系.

To investigate the genetic polymorphisms of 19 X-STR loci in the Han population in Northern China, samples from 628 unrelated individuals (314 males and 314 females) were collected and 19 X-STR loci were amplified by AGCU X19 STR System. A total of 270 different alleles were detected in 19 X-STR loci. All loci were in Hardy − Weinberg equilibrium and there was only one pair of linkage loci (DXS10103-DXS10101). There was no significant difference in allele frequency between male and female populations. The combined power of discrimination in males was 1–1.8667 × 10−13, while the combined power of discrimination in females was 1–3.6532 × 10−22. The combined mean paternity exclusion chance (CMEC) for X-chromosomal markers in father/daughter or mother/son duos Mean paternity exclusion chance (MECDesmarais Duo) was 1–5.1109 × 10−9. Moreover, the CMEC for X-chromosomal markers in trios involving daughters (MECDesmarais) was 1–2.0292 × 10−12. The compound amplification system composed of 19 X-STR in this study showed high polymorphism in the Han population of Northern China, which had a high application value in difficult genetic relationship identification.

目的建立一套五色荧光复合扩增体系，并调查中国北方汉族遗传多态性和父子家系突变情况。方法根据文献筛查出在中国某一群体中突变率为高变异和快速变异的Y-STR基因座，建立一套五色荧光Y-STR复合扩增体系，计算在500个北方汉族无关男性个体中的基因多样性，观察每个样本的Y-STR单倍型，并对中国北方汉族500个父子对进行检测，统计父子间的突变情况。结果成功构建了包含21个Y-STR基因座复合扩增检验体系，在北方汉族群体中基因多态性在0.402 3～0.990 4之间，500个无关个体中未发现有相同的单倍型。在500个父子对中观察到21个Y-STR基因座共发生134次突变，其中突变率最高的基因座是DYF399S1，为7.40×10-2；在DYS612、DYS547、DYS627、DYS526b、DYS576、DYS630、DYS449、DYF404S1、DYS390、DYS570和DYS518基因座上突变率≥1.00×10-2。此外，DYS626、DYS458和DYS439基因座突变率≥4.00×10-3。有97个父子家系出现1个基因座突变，16个家系同时出现2个基因座突变，仅有1个家系同时出现3个基因座突变，家系突变的概率为0.268。其中127次为一步突变，7次为两步突变，符合逐步突变模式。结论高变异Y-STR基因座能够有效区分具有父系亲缘关系的男性个体，可作为联合DNA索引系统（combined DNA index system，CODIS）常染色体和常规低突变Y-STR系统基因座的补充。

1 案 例 1.1 简要案情 在一起遗产继承纠纷案件中,赵1(女)、赵2 (女)、陈某(男)、赵3(男)为全同胞的兄弟姐妹,父母已故,在案件办理过程中查到邢某(女)可能为上述4人同父异母的姐姐,故法院委托本中心对邢某与赵1、赵2、陈某、赵3之间是否存在同父异母半同胞关系进行鉴定.

Complex kinship identification such as half-sibling identification is a difficult task in forensic biology Here we represented an approach in dealing with half-sisters from different mothers, with the combination of autosomal and X chromosomal short-tandem repeats (STRs) data. X chromosomal STRs can offer additional information, especially in some cases where autosomal STRs alone may not provide enough information for an accurate opinion. In this case, half-sister or unrelated relationship between two women (S1 and S2) with different mothers were distinguished. 23 autosomal and 31 X chromosomal STRs of S1, S2, S1's mother (M1), S2's mother (M2) and S1's grandmother (G1) were profiled with three different commercial kits. As to X-chromosome STRs, likelihood ratios (LRs) were calculated by FamLinkX with consideration of linkage, linkage disequilibrium, and mutations. When only the profiles of the two individuals (S1 and S2) were available, LRs between S1 and S2 were 1.1110 × 102 based on 23 autosomal STRs and 3.2257 om107 based on 31 X chromosomal STRs. When the maternal genotypes were taken into consideration, LRs increased to 2.5297 × 103 and 3.0563 × 1018. Therefore, both the DNA profiles of each mothers and X chromosomal STRs are important in dealing with the identification of half-sisters from different mothers.

This study aimed to investigate the application of autosomal short tandem repeat (STR) loci using the ITO method and discriminant function algorithm for full-sibling (FS) identification. A total of 342 pairs of full siblings (FSs) and 3900 pairs of unrelated individuals (UIs) were genotyped at 51 STR loci. The groups were in accordance with discrimination power (DP) values and the number of loci, and the values of FS index (FSI) of FSs and UIs were calculated by the ITO method. The discriminant functions of FS–UI were established using the Fisher's discriminant analysis method with SPSS 19.0 software. All the lgFSI values in the FS and UI groups followed a normal distribution, and there were significant differences between the two pairs. A higher average DP value was associated with a more significant difference, as was a greater number of STR loci detected. Receiver operator characteristic curves showed that the accuracy of FS identification can be affected by both locus polymorphism and the number of loci detected. Comparing the rate of false positives and false negatives of discriminant function between the two groups, a higher average DP value and larger number of loci detected were associated with a lower rate of miscarriage of justice and were more helpful for FS–UI identification. The ITO-based discriminant analysis method has high applicability in FS–UI tests. Testing of a greater number of STR loci promotes FS identification.

目的 探讨状态一致性(IBS)评分法在全同胞和无关个体鉴定中的可行性.方法 根据717对全同胞、812,378对无关个体的13、15和19个常染色体STR分型结果,统计各IBS评分,采用MATLAB 2019b软件拟合正态分布曲线,采用SPSS 26软件进行均数的t检验.结果 同胞对和无关个体对共有等位基因数均符合正态分布,具有显著性差异.19个检测系统,如果按照IBS≥22为"倾向于认为两名被鉴定人为全同胞"、13<IBS<22为"无法给出倾向性意见"、IBS≤13为"倾向于认为两名被鉴定人为无关个体",系统效能可达0.7661,但有0.0181％的无关个体被错误判断为全同胞.结论 IBS法在全同胞/无关个体鉴定中检测13、15和19个常染色体STR基因座中具有一定的应用价值,检测基因座越多越有利于全同胞鉴定,提高系统效能和降低错判风险.

1 案 例 1.1 案例1 1.1.1 简要案情 唐某,户籍性别"女",因"婚后2年不孕"于2003年2月至2004年3月先后多次到医院检查,B超示"子宫偏小,双侧附件未探及".回顾既往病史,1992年3月原告唐某曾因"身材矮小"到被告北京某医院治疗,入院诊断为"XY单纯性腺发育不全,睾丸退化型可能",同年4月行"剖腹探查+双侧性腺切除术".唐某认为,该医院在剖腹探查没有发现睾丸的情况下错误地将其双侧卵巢切除,致使其婚后不能怀孕,侵害了其健康权,故起诉要求医疗损害赔偿.法院委托本鉴定所进行医疗损害鉴定.