Utilizing Short Tandem Repeats (STRs) as a Resolving Matrix in Parental Dispute DNA Analysis

Interest in DNA analysis using short tandem repeats (STR) as finger printing tools in forensic medicine has gained tremendous application, as expression of these nuclear factors have enhanced forensic examination. Here we used this Biochemical characterization after conventional extraction process, polymerase chain reaction (PCR), gel electrophoresiss and a sequencer to distinguish and resolve parental dispute. The differential migration of labeled DNA fragments which attains excitation energy with a laser elicits fluorescent light of different wavelength depending on the dye used. A data collection software (Genemapper) collects raw data (spectrograph) and converts it to an electropherogram that is interpreted. By comparing the DNA profiles, inclusion and exclusion criteria were elucidated to resolve disputes. The inherent discriminating power of STRs used in analysis enhances resolution of cell mixtures, genetic aberration, substantiation of tissue origin and provides genetic distinction which is a robust and reliable approach in resolving parental disputes.

Identification and characterization of short tandem repeats in the Tibetan macaque genome based on resequencing data

The Tibetan macaque, which is endemic to China, is currently listed as a Near Endangered primate species by the International Union for Conservation of Nature （IUCN）（2017）. Short tandem repeats （STRs） refer to repetitive elements of genome sequence that range in length from 1-6 bp. They are found in many organisms and are widely applied in population genetic studies. To clarify the distribution characteristics of genome-wide STRs and understand their variation among Tibetan macaques, we conducted a genome-wide survey of STRs with next-generation sequencing of five macaque samples. A total of 1 077 790 perfect STRs were mined from our assembly, with an N50 of 4 966 bp. Mono-nucleotide repeats were the most abundant, followed by tetra- and di-nucleotide repeats. Analysis of GC content and repeats showed consistent results with other macaques. Furthermore, using STR analysis software （IobSTR）, we found that the proportion of base pair deletions in the STRs was greater than that of insertions in the five Tibetan macaque individuals （P〈0.05, t-test）. We also found a greater number of homozygous STRs than heterozygous STRs （P〈0.05, t-test）, with the Emei and Jianyang Tibetan macaques showing more heterozygous loci than Huangshan Tibetan macaques. The proportion of insertions and mean variation of alleles in the Emei and Jianyang individuals were slightly higher than those in the Huangshan individuals, thus revealing differences in STR allele size between the two populations The polymorphic STR loci identified based on the reference genome showed good amplification efficiency and could be used to study population genetics in Tibetan macaques. The neighbor-joining tree classified the five macaques into two different branches according to their geographical origin, indicating high genetic differentiation between the Huangshan and Sichuan populations. We elucidated the distribution characteristics of STRs in the Tibetan macaque genome and provided an effective method for screening polymorphic STRs. Our results also lay a foundation for future genetic variation studies of macaques.

Mapping short tandem repeats for liver gene expression traits helps prioritize potential causal variants for complex traits in pigs

Background:Short tandem repeats(STRs)were recently found to have significant impacts on gene expression and diseases in humans,but their roles on gene expression and complex traits in pigs remain unexplored.This study investigates the effects of STRs on gene expression in liver tissues based on the whole-genome sequences and RNA-Seq data of a discovery cohort of 260 F6 individuals and a validation population of 296 F7 individuals from a heterogeneous population generated from crosses among eight pig breeds.Results:We identified 5203 and 5868 significantly expression STRs(eSTRs,FDR<1%)in the F6 and F7 populations,respectively,most of which could be reciprocally validated(π1=0.92).The eSTRs explained 27.5%of the cisheritability of gene expression traits on average.We further identified 235 and 298 fine-mapped STRs through the Bayesian fine-mapping approach in the F6 and F7 pigs,respectively,which were significantly enriched in intron,ATAC peak,compartment A and H3K4me3 regions.We identified 20 fine-mapped STRs located in 100 kb windows upstream and downstream of published complex trait-associated SNPs,which colocalized with epigenetic markers such as H3K27ac and ATAC peaks.These included eSTR of the CLPB,PGLS,PSMD6 and DHDH genes,which are linked with genome-wide association study(GWAS)SNPs for blood-related traits,leg conformation,growth-related traits,and meat quality traits,respectively.Conclusions:This study provides insights into the effects of STRs on gene expression traits.The identified eSTRs are valuable resources for prioritizing causal STRs for complex traits in pigs.

A NORTHWEST DATABASE MODEL OF SHORT TANDEM REPEAT LOCI IN FORENSIC MEDICINE

Objective To establish the northwest database of short tandem repeat(STR) loci in forensic medicine. Methods Bloodstains or whole blood samples were collected from the unrelated prisoners in Xi'an city. Genetic distribution for 13 STR loci and amelogenin locus were determined in prisons based on GeneScan. One primer for each locus was labeled with the fluorescent by 5 FAM, JOE, or NED. The forensic database were generated by using multiple amplification, GeneScan, genotype, and genetic distribution analysis. Results 113 alleles and 302 genotypes were observed, with the corresponding frequency between 0.0050-0.5250 and 0.0100-0.4100. The mean H was 0.7667. The accumulative DP was 0.9999999,. The accumulative EPP was 0.9999999. The scope of PIC was 0.6036- 0.8562 . PM was less than 10 -11 . The observed and expected genotype frequencies were evaluated using χ 2 test and all were in accordance with Hardy Weinberg equilibrium ( P > 0.05 ). Conclusion STR loci is an ideal genetic marker with powerful polymorphism and stable heredity. It can be used for individual identification and paternity in forensic medicine. The forensic DNA database model can be established successfully.

Carrier Detection and Presymptomatic Identification of Wilson Disease in Chinese by Non-Isotopic Linkage Analysis with Four Short Tandem Repeat Polymorphisms

Summary: Wilson disease (WD) is an autosomal recessive disorder of copper metabolism. To establish an efficient, accurate and fast diagnostic method for carrier detection and presymptomatic identification of WD in Chinese population, we studied haplotypes of short tandem repeat (STR) polymorphisms flanking the WD gene in 40 Chinese WD families. The results suggested that this genetic diagnosis system based on the four STR polymorphisms is of high value for the detection of potential carriers and WD homozygotes in families with at least one previously affected child. It is an efficient, accurate and fast diagnostic method that can be well suited for routine use in clinical laboratories.

ALLELE DISTRIBUTION OF FIVE X-CHROMOSOME SHORT TANDEM REPEAT LOCI IN EWENKE POPULATION OF NORTH CHINA

Objective To study the allele genetic polymorphism of five short tandem repeat （STR） loci on X-chromosome in Ewenke population of north China and to provide basic data for forensic identification. Methods Genomic DNA was extracted from EDTA-whole blood of Ewenke population by Chelex-100. The DNA samples were amplified by PCR and were analyzed by polyacrylamide gel electrophoresis and silver staining. The sequence length variations of DXS6799, DXS8378, DXS101, HPRTB, and DXS6789 loci on X-chromosome in 98 unrelated Ewenke individuals were investigated. Results All five loci analyzed showed high polymorphism and genetic stability. The data of the five X-chromosome STR loci in Ewenke ethnic group of China was in accordance with Hardy-Weinberg equilibrium by Chi-square test. Conchusion Allele polymorphism of five X-chromosome STR loci can be used as a genetic marker for forensic identification and population genetic research.

Application of Short Tandem Repeat in Prenatal Diagnosis for Phenmylketonuria during the First Trimester

Objective : To find a simple and rapid way far the prenatal diagnosis of phenyUce-tonuria (PKU) during the first trimester in order to prevent inborn PKU patients as early as possible. Methods :DNA was extracted respectively from the Mood sampleps of 9 families' members and chori-onic tissues of 9 embryoes by cliorionic vittus sampling (CVS). The independent short tandem repeat (STR) alleles of members in 9 families with classic form of PKU were analyzed and prenatal diagnosis were conducted using polymerase chain reaction (PCR) together with denaturing gradient gel elec-trophoresis(DGGE)and silver dyeing. Results-.We identified 1 embryo with PKU, 2 normal individuals and 5 carriers among 9 subjects. Conclusion: Prenatal diagnosis for PKU by STR is available in the first trimester. This procedure was promising and would be widely used in Chinese population.

深圳汉族人群42个常染色体短串联重复序列基因座的遗传多态性

【目的】调查深圳汉族人群42个常染色体短串联重复序列(STR)基因座(含41个非CODIS系统STR基因座)等位基因的遗传多态性,研究其在法医鉴定中的应用价值。【方法】采用AGCU21+1和阅微MR23荧光扩增试剂盒对深圳汉族人群435个无关个体STR基因座进行序列多态性分析。通过Modified-Powerstates和arlequin v3.5软件统计等位基因频率、法医遗传学参数并进行Hardy-Weinberg平衡检验。【结果】深圳汉族人群435个无关个体共检出418个等位基因,均符合Hardy-Weinberg平衡定律(P>0.05/42),频率分布在0.0011~0.5529之间。D1S1656和D21S1270基因座多态性最高,均检出16个等位基因;D4S2408基因座检出的等位基因最少;个体识别能力(DP)为0.7988(D1S1627)~0.9686(D7S3048),多态性信息含量(PIC)为0.5680(D1S1627)~0.8598(D7S3048),杂合度(H)为0.6276(D1S1627)~0.8782(D20S470)。【结论】42个常染色体STR基因座的等位基因在深圳地区汉族群体遗传多态性较好,具有较高的个体识别能力,在个体识别和亲权鉴定尤其是单亲或出现基因突变的情况下具有较高的应用价值;所得的数据亦为STR群体遗传学提供基础数据。

脐带血造血干细胞移植患者合并COVID-19的临床特征分析

目的:探讨脐带血造血干细胞移植患者合并新型冠状病毒感染的临床特点及治疗策略,从而提升此类患者的临床诊疗水平。方法:回顾性分析16例脐带血移植患者的一般情况、临床诊断、新型冠状病毒感染特征、细胞植活时间、治疗方案以及预后。结果:15例患者以发热伴咳嗽为首发症状,均为轻型,1例为中型。14例患者造血干细胞顺利植活并出仓,1例继发植入失败但桥接同胞异基因造血干细胞移植,1例死亡。结论:新型冠状病毒感染增加了脐带血干细胞移植的难度,但仍需要更多临床数据进一步佐证。

CNV-seq结合STR技术在稽留流产遗传学病因分析中的应用

目的 本研究旨在评估将低深度全基因组拷贝数变异测序(copy number variation sequencing, CNV-seq)技术与短串联重复序列(short tandem repeat, STR)技术联合应用于稽留流产患者流产组织遗传学病因分析的效果。方法 收集2019年1月至2022年11月期间因“胚胎停育”而终止妊娠的49例稽留流产患者进行CNV-seq技术和STR分型技术的联合检测。结果 研究发现孕妇流产次数≥2次组的胚胎染色体异常率明显高于流产次数<2次组,差异有统计学意义(62.1%vs 30.0%,P<0.05),而高龄孕妇组与非高龄孕妇组的胚胎染色体的异常率差异无统计学意义(70%vs 66.7%,P>0.05)。在49例流产物中,CNV-seq结合STR技术共检出34例染色体异常,检出率为69.4%(34/49)。其中染色体数目异常的有20例,包括13例非整倍体,5例多倍体(STR技术)和2例嵌合体;染色体结构异常共有14例,其中5例检出为致病性CNV。此外,还检测到了10例临床意义不明(variants of uncertain significance,VUS)的CNV。结论 将低深度CNV-seq技术与STR技术相结合,可以有效地弥补稽留流产的染色体核型分辨率低和培养难度大等缺点,并提高检测稽留流产胚胎异常染色体的能力,明确稽留流产的遗传学病因,为再次妊娠提供更准确的指导。

STRs-PCR分型技术在法医学上的应用

短串联重复序列 (STRs)是广泛存在于人类基因组的一类具有长度多态性的DNA序列 ,属高信息基因座。概述了STRs PCR的法医学应用特点以及它们在亲子鉴定、个体识别等领域的法医学应用及其理论基础、现状和前景。

西藏藏族15个STRs位点多态性及其与其他民族群体的遗传关系

目的：研究西藏藏族人群15个短串联重复序列（short tandem repeats,STRs）位点（D8S1179,D21S11,D7S820,CSF1PO,D3S1358,TH01,D13S317,D16S539,D2S1338,D19S433,vWA,TPOX,D18S51,D5S818,FGA）的多态性分布及群体遗传学和法医学应用价值。并分析它们与西藏其他民族及其他亚洲人群间的遗传学关系。方法：采用ABI3100遗传分析仪检测STRs基因多态性,用ARLEQUIN 3.1软件计算等位基因频率和各种多态性参数。并将其结果与文献报道的其他亚洲人群的STRs结果进行比对,DISPAN软件计算遗传距离（DA）、基因分化系数（Gst）和杂合度（Ht）,MEGA4.0软件绘制进化树,SPSS14.0进行多维量表法（MDS）分析。结果：藏族群体中共检出132种等位基因,频率分布0.0050-0.5990;杂合度、个体识别力、多态性信息量等群体遗传学指标分析显示,15个STRs位点具有中度或高度多态性,中国藏族群体具有较独立的遗传结构。结论：所选择的15个STRs位点具有较高的个体识别力和多态性信息量,可用于群体遗传学和法医学研究。

皖南地区汉族人群21号染色体上2个STRs位点的多态性分析

目的:研究21号染色体上2个短串联重复序列位点(D21S11、D21S1409)在安徽皖南地区汉族人群中的遗传多态性,评价它们在唐氏综合征产前诊断中的应用价值。方法:采用聚合酶链反应、聚丙烯酰胺凝胶电泳和银染技术,对皖南地区汉族无亲缘关系的90名个体的样本进行检测。结果:D21S11和D21S1409位点均由多个等位片段构成,片段大小分别在202～260bp和173～233p之间。两个位点的观察杂合度分别为0.4778和0.6222。结论:D21S1409有较高的杂合度,可作为唐氏综合征产前诊断的遗传标志。

亲权鉴定风险防范分析

目前亲权鉴定技术比较成熟,但在鉴定过程中仍存在风险。通过统计分析山东省从事亲权鉴定的司法鉴定机构和司法鉴定人状况,从亲权鉴定受理委托主体、受理前咨询工作、部分鉴定案例分析、实验室认证认可工作的实施以及人员能力提升等方面进行分析,旨在强调司法鉴定人的专业能力对防范亲权鉴定风险的重要性。在山东省,以企业为主体的亲权鉴定机构多于以医院、高校等单位为主体的鉴定机构;部分司法鉴定人存在兼职多项其他鉴定领域业务的情况。在案件受理过程中,司法鉴定机构和司法鉴定人应进行鉴定前风险评估,从而规避风险、依法依规鉴定。同时,司法鉴定人应当进行相关的专业培训,从而提高自身的专业能力,保障鉴定结果的准确性,让科技证据为正义说话。

Y染色体短串联重复序列微流控芯片复合扩增检测体系研究

目的构建Y染色体短串联重复序列(Y-STR)微流控芯片扩增检测试剂,并进行性能验证,实现Y-STR基因座的快速全集成检测。方法使用Y-STR微流控芯片检测体系,对其灵敏度、成功率和分型准确率、峰平衡性、精准性和准确性、检材适应性、混合物检测能力和抗抑制性进行验证评估。结果DNA标准品9948的模板量≥8 ng,血卡片数≥3片以及口腔拭子刮擦次数≥7次时可获得Y-STR完整分型;165份样本的全集成检测成功率为91.52%,分型准确率为99.74%;不同荧光通道之间的峰高比值为89.81%;10次运行的等位基因分型标准品的片段大小标准差均在0.5 bp以内,20份样本全集成检测的等位基因片段和相应的等位基因标准品之间的片段准确性均在0.5 bp以内;能够对口腔拭子、血卡、唾液卡、烟蒂、血棉签、布片精斑等检材进行准确分型;混合样本中较小贡献者与较大贡献者在1∶3的比例时可获得完整基因分型;在不同浓度的腐殖酸(50~400 mg/L)、靛蓝(20~100 nmol/L)、血红蛋白(100~500μmol/L)等抑制物的干扰下,该体系可获得完整基因分型。结论该体系可应用于国产Quick TargSeq法医DNA现场快速检测系统使用,可在法医学实践中选用。

CNV结合STR分型技术检测孕早期流产组织潜在葡萄胎效果及风险因素分析

目的:评估基因组拷贝数变异测序(CNV-seq)结合短串联重复序列(STR)多态性分析技术在检测孕早期(≤9周)流产物组织中潜在葡萄胎病例的应用效果.方法:收集2021年1月-2022年12月行孕早期流产组织CNV-seq结合STR多态性检测病例114例,其中部分新鲜绒毛组织进行CNV-seq结合STR多态性检测,部分组织行病理学检测.比较两种检测方法结果,并分析潜在葡萄胎病例的临床特征和影响因素.结果:CNV-seq结合STR多态性检测共检出染色体异常病例28例,阳性率为24.6%,其中单亲二倍体(UPD)8例,占阳性病例28.6%;病理学检出葡萄胎病例12例,阳性率为10.5%,其中完全性葡萄胎(CHM)10例,占阳性病例的83.3%.两种检测方法的结果一致率为89.5%,Kappa值为0.75,两种方法具较好一致性.潜在葡萄胎病例与非葡萄胎病例在年龄、孕次、流产次、β-hCG水平、超声表现等方面有差异,其中年龄、β-hCG水平和超声表现是潜在葡萄胎危险因素(均P<0.05).结论:CNV-seq结合STR多态性分析技术能有效检测孕早期流产物组织中潜在葡萄胎病例,有助于指导临床治疗和避免再次流产.

Mutation Studies of 31 Highly Mutated Y-chromosomal Short Tandem Repeat Systems in the Han Population of Northern China

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.