Forensic and phylogenetic characterization of 15 autosomal STRs in Hazara population of Pakistan

In the current study, 217 unrelated individuals of the Hazara population were genotyped for 15 autosomal short tandem repeats to generate parentage and forensic efficacy parameters. Hazaras belong to the Shi’a sect and are recognized by their Turko-Mogholi features. We found that D2S1338 was the most discriminatory locus with a maximum power of exclusion and high value of polymorphism information content. Whilst the Combined Power of Discrimination (CPD), Combined Matching Probability (CMP) and Combined Power of Exclusion (CPE) were 0.999999999999999, 2.76796338879E^-17 and 0.999999040733479 respectively. Furthermore, the pattern of genetic affinity with genetically assumed related populations was demonstrated through Heat Map and Phylogenetic analysis, which revealed a great level of genetic closeness of Hazaras with Mongol population and descendants of Genghis Khan. The resulting data can be used for forensic applications and anthropological studies.     

Population data for 15 loci (Identifiler Kit) in a sample from the Valley of Mexico

We analyzed 242 individuals from the Valley of Mexico, including the larger and more cosmopolitan city of this country. They were PCR-typed for 15 STR loci with the AmpFlSTR Identifiler PCR Amplification Kit (Applied Biosystems). Allele frequencies for each STR were estimated and compared to previous reports. Genotype distribution by locus and by two-loci combination was in agreement with Hardy-Weinberg expectations for all fifteen STRs. This STR system in Mexican-mestizos presented a combined probability of exclusion (PE) and discrimination (PD) longer than 99.999%, respectively.     

Allele frequencies of the 15 AmpF<Emphasis Type="Italic">l</Emphasis>STR Identifiler loci in the population of Vojvodina Province,Serbia and Montenegro

The 15 AmpFlSTR Identifiler loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818 and FGA) were analyzed in the sample of 100 unrelated, autochthonous healthy adult Serbians from Novi Sad (Vojvodina Province, Serbia and Montenegro). The agreement with HWE was confirmed for all loci with the exception of D7S820 (based on the ²-test only). The combined power of discrimination (PD) and the combined power of exclusion (PE) for the 15 tested STR loci were 0.99999999999999995 and 0.9999990, respectively. According to the presented data, D2S1338 and D18S51 are the most informative markers. Based on allelic frequencies and statistical parameters for forensic testing, it may be suggested that the AmpFlSTR Identifiler detection system represents a powerful strategy for individual identification and parentage analysis in the Serbian population.     

Population data for 15 autosomal STR loci in the Miao ethnic minority from Guizhou Province,Southwest China

Fifteen autosomal short tandem repeat (STR) loci were genotyped using the AmpFISTR Identifiler PCR Amplification kit from 505 unrelated healthy individuals of Miao ethnic minority living in the Guizhou Province, Southwest China. Also, the genetic distance between Miao and nine related populations was compared.     

Sibling assessment based on likelihood ratio and total number of shared alleles using 21 short tandem repeat loci included in the GlobalFiler™ kit

Sibling assessment using the 15 autosomal short tandem repeat (STR) loci included in the Identifiler® kit can be difficult when comparing an unidentified party to an alleged sibling. Therefore, we investigated the likelihood ratio (LR) and the total number of shared alleles (TNSA) for sibship determination using the 21 autosomal STR loci included in the GlobalFiler™ kit.We computationally generated the genotypes of 10,000 sibling pairs and 10,000 unrelated pairs based on previously reported allele frequencies of the 15 Identifiler loci and the remaining 6 GlobalFiler loci. The LR and the TNSA were then calculated in each pair using the 15 and 21 loci. Next, these calculations were applied to 22 actual sibling pairs.LR values ⩾10,000 were observed in 48% of the sibling pairs using the 15 loci and in 80% of the sibling pairs using the 21 loci. The TNSA distribution between siblings and unrelated pairs was more divergent in GlobalFiler than in Identifiler. TNSA values ⩾20 were found only in true siblings in Identifiler, while TNSA values ⩾24 in GlobalFiler. In Identifiler, all pairs with TNSA ⩾24 had LR values ⩾10,000 and the same was true in GlobalFiler for TNSA ⩾29. Therefore, increasing the number of loci is very efficient for sibship determination.The LR is most reliable for determining sibship. However, TNSA values may be useful for the preliminary method of LR values because LR value demonstrated a significantly positive correlation with TNSA value in both Identifiler and GlobalFiler.     

STR profiling of epithelial cells identified by X/Y-FISH labelling and laser microdissection using standard and elevated PCR conditions

During the investigation of allegations of sexual assault, samples are frequently encountered that contain DNA from a female and a male donor. These may represent contributions of DNA from the complainant and potentially, the offender. Many semen stained samples successfully undergo DNA analysis and interpretation using a differential extraction method that separates sperm from the epithelial cells present in the stain. However, for those mixed cell samples that contain only epithelial cells, separation of any male cells from female cells is problematic. This paper describes the application of fluorescent in situ hybridisation (FISH) for the gender identification of epithelial cells and subsequent recovery of target cells using laser microdissection (LMD). The profiling results obtained from samples of known cell numbers using the Identifiler™ multiplex at standard 28-cycle PCR conditions and, when cell numbers are low, the SGM Plus™ multiplex at elevated 34-cycle PCR conditions (also known as Low Copy Number DNA analysis (LCN)) are described.     

Identifiler体系在276例单亲亲权鉴定中的应用分析

目的 探讨Identifiler体系在单亲亲权鉴定案例中的应用价值.方法 采用荧光标记STR-PCR复合扩增、毛细管电泳基因分型技术,应用3100 Avant遗传分析仪对276例单亲亲权鉴定的个体进行15个短串联重复串联序列(STR)基因座的基因分型.结果 在276例的单亲亲权鉴定中,认定亲权关系199例,占72.10%,其中亲权指数(CPI)≥2 000,父权相对机会(RCP)≥99.95%有183例,13例CPI＜2 000,3例出现一个基因座单步突变;排除亲权关系77例,占27.90%,其中2例只出现1～2个不符合遗传规律基因座,通过加测母亲样本,排除指标均大于3个.结论 应用Identifiler体系的15个STR基因座对常规单亲亲权案例能成功地开展鉴定分析工作,但当CPI＜2 000或有1～2不符合遗传规律基因座时,须增加检测基因座和加测母亲样本,以提高亲权指数或增加排除指标,规避可能的错误鉴定结论 .     

运用Identifiler试剂盒对硅珠法提取石蜡包埋组织DNA质量的评估

目的:运用硅珠法从石蜡包埋的组织中提出DNA,Identifiler试剂盒评估DNA质量?方法:南京医科大学第一附属医院病理科2009~2011年石蜡包块49例,运用硅珠法提取石蜡包埋组织DNA,通过紫外分光光度计测定DNA纯度和Identifiler试剂盒PCR后3130型毛细管电泳仪分析提取DNA片段的完整性?结果:经紫外分光光度计测定胃癌组织D(260 nm)/D(280 nm)均值为1.84 ± 0.02,肺癌组织为1.85 ± 0.02,甲状腺癌组织为1.82 ± 0.02,3组间比较P > 0.05,因此硅珠法提取石蜡包埋组织DNA不会因组织差异而影响提取效果;Identifiler试剂盒PCR后毛细管电泳显示其提取效果,46例(93%)得出完整的16个基因座STR峰型?结论:硅珠法可应用于多种组织的DNA提取,并保证提取DNA样品的纯度和完整度?     

A selection guide for the new generation 6-dye DNA profiling systems

The Federal Bureau of Investigation (FBI) has recently expanded the CODIS core loci from the existing 13 to 20 as a new guideline, and laboratories from the US are required to comply with the new regulation before uploading or conducting identity search in the national database. The expanded CODIS format, which shares all the core loci commonly used in the European countries and the US, not only increases international compatibility, but also reduces the number of adventitious matches, and hence facilitates international law enforcement and counterterrorism endeavours. Here, we review the key performance measures of three new STR amplification systems with 6-dye chemistry, namely, the Investigator 24plex QS Kit from QIAGEN, the GlobalFiler™ PCR Amplification Kit from Applied Biosystems™, and the PowerPlex^® Fusion 6C System from Promega. Our results have demonstrated that GlobalFiler displays the highest sensitivity among the tested kits, whereas Investigator 24plex shows a higher tolerance to common PCR inhibitors including Humic acid and Tannic acid. GlobalFiler and Fusion 6C, on the other hand, yield DNA profiles with better heterozygous peak height and intra-colour signal balance. Both GlobalFiler and Investigator 24plex exhibit slightly higher sensitivity than Fusion 6C in the profiling of minor components in DNA mixture, but the latter displays a higher consistency in the preservation of the mixture ratio. In summary, our work has demonstrated that these three profiling systems have their different performance features, and hence it is recommended that laboratories should select the most suitable kits according to their own requirements and operational needs.