Y-chromosome STR system, Y-PLEX 12, for forensic casework: development and validation

The Y-PLEX 12 system, developed for use in human identification, enables simultaneous amplification of eleven polymorphic short tandem repeat (STR) loci, namely DYS392, DYS390, DYS385 a/b, DYS393, DYS389I, DYS391, DYS389II, DYS 19, DYS439 and DYS438, residing on the Y chromosome and Amelogenin. Amelogenin provides results for gender identification and serves as internal control for PCR. The validation studies were performed according to the DNA Advisory Board's (DAB) Quality Assurance Standards. The minimal sensitivity of the Y-PLEX 12 system was 0.1 ng of male DNA. The mean stutter values ranged between 3.76-15.72%. A full male profile was observed in mixture samples containing 0.5 ng of male DNA and up to 400 ng of female DNA. Amelogenin did not adversely affect the amplification of Y-STRs in mixture samples containing male and female DNA. The primers for the Y-STR loci present in Y-PLEX 12 are specific for human DNA and some higher primates. None of the primate samples tested provided a complete profile at all 11 Y-STR loci amplified with the Y-PLEX 12 system. Y-PLEX 12 is a sensitive, valid, reliable, and robust multiplex system for forensic analysis, and it can be used in human forensic and male lineage identification cases.     

10个STR基因座荧光复合扩增体系的研制

目的建立10个STR基因座荧光标记复合扩增体系,并评价其法医学应用价值。方法在北京、山西、广东汉族,辽宁满族、西藏藏族群体中调查STR基因座遗传多态性,筛选出9个具有高度多态性和法医应用价值的STR基因座及性别基因座。构建四色荧光素标记复合扩增体系,制备等位基因分型标准物,编制分析软件,并对体系的种属特异性、灵敏度、稳定性、混合样本等检测能力进行考察。结果建立的复合扩增体系遗传稳定好,累积非父排除率可达0.999 96,累积个体识别率可达0.999 999 999 999 3;与CODIS系统均不存在连锁遗传;各基因座间布局合理、无杂峰、扩增结果清晰易辨,并可实现检测分析自动化。体系种属特异性较好,灵敏度为0.1ng,稳定性好,混合样本检出范围在2∶8～8∶2之间。实际案例检材检测结果好。结论本文建立的复合扩增体系在法医学实践中有较好的应用价值。     

云南汉族人群11个Y-STR基因座遗传多态性调查及法医学应用

目的调查11个Y-STR基因座及其单倍型在云南汉族人群中的遗传多态性分布,探讨其法医学应用价值,为法医学应用提供基础数据。方法应用Powerplex!Y系统对云南汉族201名无关男性个体进行11个Y-STR基因座的复合扩增,用ABI310型基因分析仪对扩增产物进行检测,统计其群体遗传学参数。结果Powerplex!Y系统前10个Y-STR基因座分别检出3、5、6、8、5、4、5、8、4、7个等位基因,DYS385a/b基因座检出56种单倍型;GD值最低为0.4273(DYS438),最高为0.9747(DYS385a/b);观察到11个Y-STR基因座共同构成的单倍型175种,其中有154种单倍型只出现1次,16种出现2次,5种出现3次,累计GD值为0.9984。结论11个Y-STR基因座具有较强的个体识别能力,可应用于云南地区汉族人群的个体识别与亲权鉴定。     

浙江汉族人群6个Y—STR基因座的遗传多态性调查及法医学应用

目的获得6个Y-STR基因座及其单倍型在浙江汉族人群中的遗传多态性分布,并探讨其法医学应用价值。方法应用Y-plex荧光标记复合扩增系统,对浙江汉族200名无关男性个体进行6个STR基因座的复合扩增,用ABI3100型基因分析仪对扩增产物进行检测,统计6个Y-STR基因座的群体遗传学参数。结果其中5个Y-STR基因座分别检出5、7、6、6、5个等位基因,DYS385基因座检出47种单倍型,GD值最低为0.4275(DYS391),最高为0.9584(DYS385);观察到6个Y-STR基因座共同构成的单倍型159种,其中有132种单倍型只出现1次,16种出现2次,6种出现3次,2种出现4次,2种出现5次,累计GD值为0.9967。结论6个Y-STR基因座具有较强的个体识别能力,可应用于浙江法庭科学中的个体识别与亲权鉴定。     

Validation of nine non-CODIS STR loci for forensic use in a population from Central Poland

The D7S1517, D3S1744, D12S391, D2S1360, D6S474, D8S1132, D5S2500, D10S2325 and D4S236613 are STR loci potentially useful for forensic purposes whose analysis has recently become facilitated by availability of a commercial kit. The purpose of the study was to evaluate the usefulness of these loci for forensic identification in a population of Central Poland. The distribution of alleles of the nine STRs was determined in sample of 353 unrelated individuals born in Central Poland and indices of forensic informativeness were calculated. The studied loci were highly informative and did not show departures from Hardy-Weinberg equilibrium. For the loci located on the same chromosomes (D2S1360, D3S1744 D4S2366, D5S2500, D7S1517, D8S1132, D12S391) as other loci commonly used for identification purposes (TPOX, D2S1338, D3S1358, FGA, D5S818, D7S820, D8S1179 and D12S391) appropriate pairwise analysis of linkage disequilibrium was performed. In all cases no statistically significant deviation from independence was found. We conclude that the studied STRs are informative and, when necessary, can be used to extend the results obtained with other STRs commonly analyzed for identification purposes, in particular the CODIS set.     

Validation and implementation of the PowerPlex 16 BIO System STR multiplex for forensic casework

The PowerPlex 16 BIO multiplex short tandem repeat (STR) system contains the 13 CODIS loci (FGA, TPOX, D8S1179, vWA, D18S51, D21S11, TH01, D3S1358, CSF1PO, D16S539, D7S820, D13S317, and DS5S818), plus two pentanucleotide repeat loci (Penta D and Penta E) and the sex-identifying locus. Amelogenin. The PowerPlex 16 BIO System is optimized for use with the Hitachi FMBIO gel imaging systems. A consortium of seven independent laboratories collaborated to perform the studies defined by the FBI standards for performing a developmental validation, including the evaluation of sample concordance, percent stutter determination, nonprobative casework, precision, sensitivity, mixture determination, effect of substrates, the impact of environmental insults, and species specificity. All samples tested for concordance were consistent except for one sample from the Virginia Division of Forensic Science database that displayed discordance at D13S317, a locus whose primer sequence was altered. Stutter values were comparable to those of other STR multiplex systems, the precision was comparable to other multiplexes analyzed by gel electrophoresis, the DNA profiles were unchanged by the substrate upon which the blood samples were placed, and the nonprobative casework samples re-typed for the PowerPlex 16 BIO System were consistent with previous typing results. When greater than 0.125 ng of DNA was placed into the PowerPlex 16 BIO System amplification reaction, a full profile was generated by all laboratories. The mixture study results were comparable to those reported for other multiplex systems, the environmental study demonstrated a loss of larger molecular weight loci when samples were incubated at elevated temperatures for a prolonged period of time, and the only notable cross species hybridization was observed with primate DNA samples. This extensive validation work performed demonstrates that the PowerPlex 16 BIO System provides STR data of a quality comparable with other PowerPlex STR multiplex kits as well as other widely used STR multiplexes and is thus suitable for evidentiary casework analysis as well as database sample profiling.     

15重快速STR复合扩增体系的构建

目的建立一套15重快速STR复合扩增体系。方法选择14个常染色体基因座以及1个性别基因座,采用Fast Start Taq DNA聚合酶系统,以DNA标准品9947A为模板,通过筛选扩增条件、选择热启动酶用量、调整引物平衡、优化快速扩增程序、筛选反应缓冲液、选择反应体系以及筛选添加剂等一系列复合扩增实验,比较各条件下等位基因丢失和非特异性扩增情况。结果在以1 ng DNA为模板、0.4μL聚合酶及10×Fast Start高保真反应缓冲液构成10μL快速体系的条件下,32 min即可获得标准DNA全部15个STR基因座的完整分型,无等位基因丢失和非特异性扩增现象,等位基因均衡性良好。同时,5%甘油、0.01%明胶、0.05%明胶和5 mmol/L硫酸铵可作为PCR扩增过程中拟加入的反应添加剂。结论本研究建立的15重快速STR复合扩增体系可以明显缩短反应时间,提高样品检测效率。     

Development of a 24-plex Y chromosomal STR loci typing system

Y-chromosomal short tandem repeat (Y-STR) loci can play important roles in forensic casework and paternity testing. In our paper, 24-plex Y-STR typing system, which includes 3 loci (DYS635 and DYS385a/b) existed in current widely available commercial kits and 21 additional loci (DYS531, DYS630, DYS622, DYS552, DYS510, DYS449, DYS459a/b, DYS446, DYS443, DYS587, DYS527a/b, DYS460, Y-GATA-A10, DYS520, DYS557, DYS522, DYS481, DYS570, DYS444) was established with 5-dye fluorescence labeling. 200 unrelated Chinese Han males were successfully genotyped with the system and 198 haplotypes were observed. The gene diversity of each locus ranged from 0.55 (DYS531) to 0.96 (DYS385a/b), the haplotype of diversity was 0.9998 for these 24 Y-STR loci. The established 24-plex Y-STR typing system is proved to be stable and efficient in forensic DNA typing.     

Validation of the STR system FXIIIB for forensic purposes in an Austrian population sample

The short tandem repeat system FXIIIB was amplified by the polymerase chain reaction (PCR) on blood samples from 201 unrelated Austrians and analyzed by horizontal, non-denaturing polyacrylamide gel electrophoresis. The mean exclusion chance was 0.496, the discriminating power 0.883 and the heterozygosity rate 78.61%. In 50 families (100 meioses) no mutations were found. Sufficient amplification could be achieved with as little as 80 pg of high molecular weight cell line DNA, which could be reduced to 60 pg by using 32 instead of 30 cycles. By reamplifying 1 μl for another 15 cycles, the threshold could be reduced to less than 20 pg. Nevertheless this sensitivity was only possible with cell line DNA, since reamplification of simulated stains proved to be problematical due to artifacts. In a degradation experiment, DNA extracted from bloodstains stored for up to 26 days in a moist chamber and DNA boiled for up to 18 min could be amplified. A quadruplex PCR with VWA, FES and amelogenin is proposed.     

Data on nine STR loci used for forensic and paternity testing in the Greek Cypriot population of Cyprus.

Allele frequencies for the nine STRs included in the AMPFlSTR kit were obtained from a sample of 152 unrelated Greek Cypriot from the Mediterranean island of Cyprus     

Y-chromosome STR haplotypes from a Western Mediterranean population sample

Nine Y-chromosome STRs were investigated in a male population sample from the Western Mediterranean region of Valencia (Eastern Spain). Complete nine Y-chromosomal STRs haplotypes were obtained in 140 individuals, among which 113 different haplotypes were observed. The most common haplotype was shared by 5% of the sample, while 99 haplotypes were unique. The gene diversity was 0.9892 and the discrimination capacity was 0.8071. Significant population differences were observed with respect to other Iberian populations, such as the Basques and Northern Portugueses.     

Y-chromosome STR haplotypes in a southwest Spain population sample

The Y-chromosome polymorphism of eight STRs (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392; DYS393, DYS385) were studied in 111 unrelated individuals from the population of southwest Spain. The most common haplotype was shared by 3.6% of the sample, while 99 haplotypes were unique. The gene diversity was 0.9977.     

珠海地区汉族人群10个Y-STR基因座的多态性

目的 调查珠海地区汉族人群10个Y-STR基因座及其单倍型的遗传多态性，探讨其法医学应用价值。方法 应用Y-PLEX荧光标记复合扩增系统，对珠海地区汉族200名无关男性个体进行10个Y-STR基因座的复合扩增，用ABI310型基因分析仪对扩增产物进行检测，统计10个Y-STR基因座的群体遗传学参数。结果 9个Y-STR基因座分别检出5、6、6、5、4、5、5、5、7个等位基因，DYS385基因座检出44种单倍型；GD值最低为0.3904(DYS391)，最高为0.9497(DYS385)；10个Y-STR基因座共同构成的单倍型161种，其中134种单倍型只出现1次，20种单倍型出现2次，3种单倍型出现3次，3种单倍型出现4次，1种单倍型出现5次，累计GD值为0.9948。结论 10个Y-STR基因座具有较高的个体识别能力，可应用于法庭科学中的个体识别与亲权鉴定。     

Distribution of Y-chromosome STR defined haplotypes in Iberia

Seven Y-specific STR loci (DYS19, DYS389I, DY5389II, DYS390, DYS391, DYS392 and DYS393) were studied in five populations from the Iberian Peninsula: Andalusia, Valencia, Basque Country, Galicia and Northern Portugal. Haplotype and allele frequencies of these seven Y-chromosome STRs were estimated. Observed haplotype diversities are in a range between 0.96 (Basque Country) and 0.99 (Valencia and Andalusia). Significant population differentiation was registered between Basques and all the other Iberian populations and also between Valencia and Northern Portugal.     

五色荧光标记20个基因座复合扩增体系及法医学应用

目的建立20个基因座五色荧光标记复合扩增检测体系,并评价其法医学应用价值。方法收集368份无关人血样及55份实际案例样本(包括血斑、体液斑、组织及毛发),采用五色荧光素标记技术,对Amelogenin和19个STR基因座(D19S433、D5S818、D21S11、D18S51、D6S1043、D3S1358、D13S317、D7S820、D16S539、CSF1PO、Penta D、vWA、D8S1179、TPOX、Penta E、TH01、D12S391、D2S1338和FGA)进行基因型检测,并考察方法的一致性、灵敏度、种属特异性及检材适用性。结果本文五色荧光标记复合扩增检测体系可对所选20个基因座分型,结果稳定准确,且均衡性良好、无杂峰;群体调查显示累积个人识别率和累积非父排除率分别是0.999 999 999 999 999 999 999和0.999 999 99;灵敏度达125pg,种属特异性高,实际案例检材分型成功率高。结论本文五色荧光标记复合扩增检测体系各项指标可达到当前商品化试剂盒的检测水平,具有重要的法医学应用价值。