Polymorphism analysis of D6S366 STR locus

The polymorphic STR locus D6S366 was analyzed using PCR and PAG electrophoresis and 7 alleles were detected from 200 unrelated individuals in Wuhan. The allete distribution of the locus was in accordance with Hardy-Weinberg equilibrium. The H, Dp, P, E, and PIC of the D6S366 were calculated in this paper.     

Experiences with single locus DNA probes in casework.

DNA profiling in this laboratory has been employed primarily in cases of sexual assault and the largest category of items examined has been internal vaginal swabs. 79% of these gave a profile which was different from that of the victim. Results have been obtained from swabs taken up to 70 h after intercourse. In cases where DNA results were obtained, one or more suspects were excluded in 29% of the cases.     

常用STR基因座突变的观察与分析

目的观察与分析常用STR基因座突变的特点。方法从1211例确定亲子关系的案例中收集到27个突变基因。用银染法和荧光标记试剂盒复核,并作序列测定证实。结果27个突变基因出现在15个基因座,突变方式符合步移突变模型。男女性别比例8∶1。突变率与父亲年龄正相关。结论突变率与基因座各等位基因均一重复单位个数的几何平均数相关,数值高的突变率较高,亲子鉴定中应谨慎使用。     

STR和性别位点PCR产物的荧光自动检测

运用荧光染料标记引物、变性聚丙烯酰胺凝胶电泳 (denaturingpolyacrylamidegelelec trophoresis,denaturingPAGE)结合荧光法检测6个STR位点 (vWA31A、TH01、F13A1、FES、TPOX、CSF1PO)及1个性别鉴定位点(Amelogenin) ,就荧光自动检测的重复性、准确性、分辩力等方面进行了研究 ,建立了6个STR位点等位基因判定视窗及用荧光DNA测序仪进行STR分析的方法 ,实现电脑自动判读结果。结果表明 ,本文所述STR和性别鉴定的自动检测方法可靠、分辨力高 (可达1bp) ,所得数据有助于荧光自动DNA分型软件系统的数据积累。     

Recovery and STR amplification of DNA from RFLP membranes

Restriction fragment length polymorphism (RFLP) techniques were utilized in the forensic DNA community until the mid 1990s when less labor-intensive polymerase chain reaction short tandem repeat (PCR STR) techniques became available. During the transition from RFLP technology to PCR-based STR platforms, a method for comparing RFLP profiles to STR profiles was not developed. While the preferred approach for applying new technology to old cases would be to analyze the original biological stain, this is not always possible. For unsolved cases that previously underwent RFLP analysis, the only DNA remaining may be restriction cut and bound to nylon membranes. These studies investigate several methods for obtaining STR profiles from membrane bound DNA, including removal of bound DNA with bases, acids, detergents, various chemicals, and conventional cell extraction solutions. Direct multiplex STR amplification of template in the membrane-bound state was also explored. A partial STR profile was obtained from DNA that was recovered from an archived membrane using conventional extraction buffer components, indicating promise for recovering useful STR information from RFLP membranes that have been maintained in long-term frozen storage.     

Sequence analysis of STR polymorphisms at locus ACTBP2 in the Taiwanese population

A highly polymorphic sequence structure is reported in the human beta-actin related pseudogene 2 (ACTBP2) (SE33) locus in members of the Taiwanese Han population. A total of 100 unrelated members of the Taiwanese Han population were used in the study. Alleles that shared the same size but differ in their sequence are described to allow for inter laboratory sharing of data. PCR products amplified from this locus were separated by single-strand conformation polymorphism electrophoresis, the single-stranded DNA bands were excised from the gels, a second amplification performed, and then the PCR products were sequenced. All the alleles differed by either 2 or 4 bp. Sequence variations were observed as deletions or insertions in the repeat units AG (or AA) and AAAG. Additionally, transitions in the flanking regions were recorded. A total of 27 alleles with 71 associated genotypes were recorded if the alleles were defined by size, but 68 alleles with 88 associated genotypes were noted with the alleles were scored on the basis of sequence variation. The power of discrimination (Pd) of this single locus was 0.9874 making the human ACTBP2 a good alternative marker for individual identification and paternity testing.     

Rapid STR analysis of single source DNA samples in 2 h

The establishment of offender DNA databases is critical to future crime prevention. Many countries have established databases or are in the process of passing database legislation. With new legislation the number of samples that will be collected could begin to exceed the testing capacity of many labs leading to backlogs.Two bottlenecks in the workflow that can contribute to a backlog of samples are DNA purification and PCR cycling time. The average purification time is approximately 2 h and the average cycling time of current STR kits is approximately 3 h. To address the second problem we investigated alternative DNA enzymes to decrease PCR cycling time. It was necessary to balance the increase in time to result against the need to address factors which can impact interpretation of a DNA profile such as: generation of stutter products, non-template addition, intra-locus balance, accuracy, and species specificity.Initial feasibility studies demonstrate that alternative enzymes can decrease PCR cycling time. The data show that this assay can increase throughput, providing results in less than 2 h. However, decreasing PCR cycling time will have an affect on multiplex STR performance.     

Sequence analysis of STR polymorphisms at locus ACTBP2 in the Taiwanese population

A highly polymorphic sequence structure is reported in the human beta-actin related pseudogene 2 (ACTBP2) (SE33) locus in members of the Taiwanese Han population. A total of 100 unrelated members of the Taiwanese Han population were used in the study. Alleles that shared the same size but differ in their sequence are described to allow for inter laboratory sharing of data. PCR products amplified from this locus were separated by single-strand conformation polymorphism electrophoresis, the single-stranded DNA bands were excised from the gels, a second amplification performed, and then the PCR products were sequenced. All the alleles differed by either 2 or 4 bp. Sequence variations were observed as deletions or insertions in the repeat units AG (or AA) and AAAG. Additionally, transitions in the flanking regions were recorded. A total of 27 alleles with 71 associated genotypes were recorded if the alleles were defined by size, but 68 alleles with 88 associated genotypes were noted with the alleles were scored on the basis of sequence variation. The power of discrimination (Pd) of this single locus was 0.9874 making the human ACTBP2 a good alternative marker for individual identification and paternity testing.     

Specificity of sibship determination using the ABI Identifiler multiplex system

Fifty known siblings and fifty unrelated pairs were genotyped using the ABI Identifiler STR system and sibship indices computed for each pair. Combined sibship indices (CSIs) for the known siblings ranged from less than 10 to greater than 1 billion. CSIs for the unrelated pairs ranged from 4.5 x 10(-8) to 0.12. In the known sibling group the percentage of loci where both alleles matched was approximately 40%, while the percentage of loci where neither matched was approximately 10%. In the non-sibling group, the percentage of loci where both alleles matched was approximately 6%, while the percentage of loci where neither matched was approximately 45%. Interestingly, the percentage of loci where a single allele matched was the same in both the known siblings and unrelated pairs, approximately 50%.     

Triallelic patterns in STR loci used for paternity analysis: evidence for a duplication in chromosome 2 containing the TPOX STR locus

We report triallelic patterns in several short tandem repeat (STR) loci revealed by routine paternity testing using the commercial AMPFlSTR Profiler and AMPFlSTR SGMplus kits. One case where the TPOX-locus (2p25.3) produced three peaks from the blood sample of a child was analysed further. Quantitative polymerase chain reaction (QPCR) and STR typing of the DNAs of the family trio revealed a large (>1.59 Mb) duplication flanking the TPOX-locus in chromosome 2 in both the mother and child. The implications of such genetic anomalies for paternity testing are discussed.     

汉族人群DXS9898基因座的遗传多态性

目的研究汉族群体DXS9898基因座的遗传多态性,为法科学应用提供基础数据。方法应用PCR及PAG电泳技术,对成都地区汉族群体199名女性无关个体及97名男性无关个体进行群体遗传学调查。结果共检出6个等位基因,片段大小为189～214bp,其基因型分布符合Hardy-Weinberg平衡。家系调查证实等位基因的传递遵循孟德尔遗传规律。女性样本杂合度为0.5930;男、女性样本个人识别能力(Dp)分别为0.5667、0.9420;父-母-女三联体鉴定的非父排除率(PE)为0.5862。结论DXS9898基因座在法科学个人识别及女性小孩的亲权鉴定中具有较高的实用价值。     

Investigation of the between-gel and within-gel variation in fragment size determinations found when using single locus DNA probes.

Measurement variation in the sizing of DNA fragments has been assessed, examining within-gel and between-gel variability. Also, measurement variation detected between two different laboratories, using both manual and automated measurement techniques, has been investigated and discussed.     

Problems of assessing sibship probabilities by means of genetic analysis

Nowadays, kinship studies based only on STR analysis are a very common practice. Apart from regular paternity cases, there is a rising number of cases in which the type of sibship between two persons has to be determined. Very often the parents or further relatives are unavailable for testing, so that the probability e. g. for a half-sibship has to be calculated as a deficiency situation. 50 unrelated persons (Group 1), 50 full siblings (Group 2), and 50 half-siblings (Group 3) were genotyped using the 15 STRs comprised by the AmpFlSTR Identifiler multiplex PCR-kit to investigate the reliability of common statistics programs and the indicative value of the calculated probabilities. Using a commercially available statistics program, we calculated probabilities for the following hypotheses: 1. The persons investigated are full siblings; 2. the persons investigated are half-siblings; 3. the persons investigated are unrelated. After STR analysis, half-sibling probabilities between 0.03 %-97.56% for group 1, between 0.01%-78.46% for group 2, and between 24.28%-90.18% for group 3 were calculated. In addition, the authors present two complicated deficiency cases which could be resolved only by extensive DNA typing using X- and Y-chromosomal loci, respectively, as well as the investigation of further relatives. The results of this study suggest that typing of autosomal STRs alone is no sufficient tool for resolving cases of possible half-sibship, even if probabilities of more than 90.0% are obtained. Due to the results of our study we suggest the implementation of mandatory standards for the investigation and interpretation of complicated kinship cases.     

中国5个汉族群体PentaD和PentaE基因座的遗传多态性

目的研究PentaD、PentaE基因座在中国广西、湖南、河南、四川、台湾汉族5个群体遗传多态性,比较它们之间的遗传学差异。方法用ProwerPlex(?)16 System荧光标记试剂盒(Promega公司)检测其多态性。结果PentaD、PentaE基因座在5个群体共646名无关个体中分别检出10、19个等位基因,PentaD在湖南汉族首次检出等位基因19。PentaE在河南汉族首次检出等位基因7。PentaD和PentaE在各群体的期望杂合度分别为0.7746～0.8047和0.9005-0.9219,多态信息含量(PIC)为0.7710～0.8025和0.8969-0.9176,个体识别率为0.9223-0.9341和0.9471-0.9782,非父排除率(PE)为0.5435-0.6325和0.6785-0.8465。结论PentaD、PentaE是高度多态性STR基因座,在法医学中有重要应用价值。     

STR复合扩增及荧光检测技术在个体识别中的应用

目的 :使用 310型遗传分析仪对D3S1358等 10个位点进行基因型检测并应用于法医物证学个体识别案件。方法 :用PCR复合扩增结合四色荧光检测技术对样本DNA进行基因分型。结果 :常见物证检材可成功地得到检验。结论 :这些位点适用于法医物证学个体识别。     

Typing of STR locus in biological objects with pronounced degeneration: analysis of DNA in exhumed remains of victims of war actions

The authors describe some specific features of enzymatic amplification typing of DNA preparations obtained from degraded tissues of remains of humans, which were brought from regions of war actions in the Chechen Republic. Special attention is paid to the specific artefact of polymerase chain reaction, for the first time detected by the authors in examinations of the above-mentioned objects. This so-called "ladder" effect manifesting by simultaneous nonspecific amplification of many variants of allele fragments of the STR locus on the individual DNA matrix, which can be erroneously interpreted as an evidence of mixed DNA preparation, is apparently characteristic of individual objects with pronounced degradation of biological material. Such phenomena were observed in typing of STR locuses in biological tissues subjected to biological, thermal, and physicohemical degradation. The phenomenon was studied in detail.     

STR analysis of degraded DNA using a miniplex

Analysis of short tandem repeat (STR) markers currently represents the most useful instrument in the field of forensic genetics. The problem with forensic material is the degradation of the sample material. In recent years, several papers have demonstrated that short amplicon STR (miniSTR) represents one of the most useful tools for analyzing degraded DNA samples.In the present study, we attempted to develop a short amplicon STR multiplex system (autosomal and y-chromosomal) for analyzing degraded DNA using some newly designed primer sets for a multiplex polymerase chain reaction (PCR) systems for typing.An assay of degraded DNA samples using the designed multiplex systems, including artificially degraded samples and degraded forensic casework samples, proved remarkably effective. Comparing the multiplex with commercial kits, first results show a well success rate.     

重庆地区汉族群体Amelogenin及9个STR基因座的群体遗传学调查

对重庆地区汉族群体200例无关个体进行Amelogenin及9个STR基因座群体遗传学调查,并对人血液（痕）、精斑、组织、染色的细胞涂片、毛发、牙齿及骨骼组织进行基因型测定,并用于法科学检查。采用Chelex或酚-氯仿提取DNA荧光标记复合扩增法对Amelogenin及9个STR基因座,即D3S1358、VWA、FGA、TH01．TPOX、CSF1PO、DSS818、D135317、D75820进行复合扩增,扩增产物由毛细管电泳进行分离和荧光检测。9个STR基因座分别发现6、7、17、7、5、8、7、7、7个等位基因,其最高的基因频率分别是0．3900、0．2480、0．1650、0．5380、0．5280、0．4500、0．3140、0．3150、0．4000。发现的基因型数分别是16、25、71、20、12、22、26、22、26个。基因型频率均符合Hardy－Weinberg平衡,未发现基因连锁。9个STR基因座的DP值分别是0．8610、0．9220、0．9750、0．8020、0．7730、0．8780、0．9210、0．9140、0．8990,累计DP值是0．9999;非父排除率分别是0．5990、0．5450、0．7650、0．2950、0．3620、0．4520、0．6840、0．6660、0．5180,累积非父排除率是0．9995;杂合度分别是0．8000、0．7700、0．8850、0．6030、0．6550、0．7150、0．8440、0．8350、0．7550,累积杂合度是0．9999。证明这些基因座均适用于重庆