Population data of the AmpFlSTR® NGM™ loci in South Portuguese population

Allele frequencies and other relevant forensic parameters for 15 loci studied with AmpFlSTR(R) NGM™ kit were calculated in a population of individuals residing in the south of Portugal. Blood stain samples were obtained from a total of 452 unrelated individuals involved in paternity testing casework. The kit has five loci – D10S1248, D22S1045, D2S441, D1S1656 and D12S391 not present in any other kit used in our laboratory (Powerplex 16 System and Identifiler Plus). In our laboratory, this new kit is used as a screening tool to solve deficient cases as fatherless paternity test, and to help in paternity investigations with only one genetic incompatibility after the use of routine seventeen loci. Furthermore, this five loci included in the European Standard Set are also recommended by the European Network of Forensic Science Institutes “ENFSI” and the European DNA Profiling group “EDNAP”. These studies are necessary to calculate statistical forensic parameters such as power of discrimination, power of exclusion, minimum allele frequency. Statistical parameters such as heterozigoty, homozigoty and combined power of exclusion were determinated. This kind of study is part of the Quality Program for Certificated Forensic Laboratories.     

Population genetic analyses of the STR loci of the AmpFlSTR NGM SElect™ kit for Han population in Fujian Province, China

Allele frequencies and forensically relevant population statistics of the STR loci in the AmpFlSTR® NGM SElect? PCR Amplification Kit were estimated for the Han population from Fujian province in China (n?=?454). All loci were highly polymorphic and the cumulative match probability was 5.4?×?10^?21. No significant departure from Hardy–Weinberg equilibrium and linkage equilibrium was detected after correction for sampling. The population substructure of Fujian Han population is minor.     

Forensic evaluation of the AmpFlSTR® NGM™ loci in Lodz region of Poland population sample

The paper is focused on population data for 15 polymorphic STR loci included in the NGM^TM amplification kit, obtained from a sample of 800 individuals from the Lodz region of Poland. Main statistical parameters of forensic interest were calculated and Hardy–Weinberg equilibrium was verified for each locus. Departure from HWE was not significant after applying Bonferroni corrected significance level for multiple testing (p?=?0.0033). Comparative analysis between chosen populations was performed and some significant differences were found among investigated populations. Obtained values of parameters for NGM? multiplex amplification kit point to wide range of possible applications of investigated STR markers to forensic genetics.     

Population genetic analyses of the Powerplex® Fusion kit in a cosmopolitan sample of Chubut Province (Patagonia Argentina)

Allele frequencies and forensic parameters for 22 autosomal STR loci and DYS391 locus included in the PowerPlex^® Fusion System kit were estimated in a sample of 770 unrelated individuals from Chubut Province, southern Patagonia. No significant deviations from Hardy–Weinberg equilibrium were observed after Bonferroni’s correction. The combined power of discrimination and the combined probability of exclusion were >0.999999 and 0.999984, respectively. Comparisons with other worldwide populations were performed. The MDS obtained show a close biological relation between Chubut and Chile. The estimated interethnic admixture supports a high Native American contribution (46%) in the population sample of Chubut. These results enlarge the Argentine databases of autosomal STR and would provide a valuable contribution for identification tests and population genetic studies.     

Population genetic data of the AmpFℓSTR® Identifiler® Plus and PowerPlex® 16 HS STR loci in four Canadian populations

Allele frequencies and forensically relevant population statistics were estimated for the short tandem repeat (STR) loci of the AmpF?STR® Identifiler® Plus and PowerPlex® 16 HS amplification kits, including D2S1338, D19S433, Penta D, and Penta E, for three First Nations Aboriginal populations and for Caucasians in Canada. The cumulative power of discrimination was ≥0.999999999999984 and the cumulative power of exclusion was ≥0.999929363 for both amplification systems in all populations. No significant departure from Hardy–Weinberg equilibrium was detected for D2S1338, D19S433, Penta D, and Penta E or the 13 Combined DNA Index System core STR loci after correction for multiple testing. Significant genetic diversity was observed between these four populations. Comparison with published frequency data for other populations is also presented.     

Population genetic data and forensic parameters of the 27 Y-STR panel Yfiler® Plus in Russian population

International Journal of Legal Medicine - This is the first report of a nation-wide study of the 27-STR Yfiler® Plus panel in the population of the Russian Federation. A total of 691 unrelated...     

Population genetic data for 21 autosomal STR loci in the Azerbaijani population using the Globalfiler™ kit

International Journal of Legal Medicine - The Republic of Azerbaijan is located in the southern Caucasus mountains, a region which is linguistically and ethnically diverse. We report allele...     

Evaluation of the Illumina® Beta Version ForenSeq™ DNA Signature Prep Kit for use in genetic profiling

While capillary electrophoresis-based technologies have been the mainstay for human identity typing applications, there are limitations with this methodology’s resolution, scalability, and throughput. Massively parallel sequencing (MPS) offers the capability to multiplex multiple types of forensically-relevant markers and multiple samples together in one run all at an overall lower cost per nucleotide than traditional capillary electrophoresis-based methods; thus, addressing some of these limitations. MPS also is poised to expand forensic typing capabilities by providing new strategies for mixture deconvolution with the identification of intra-STR allele sequence variants and the potential to generate new types of investigative leads with an increase in the overall number and types of genetic markers being analyzed. The beta version of the Illumina ForenSeq DNA Signature Prep Kit is a MPS library preparation method with a streamlined workflow that allows for targeted amplification and sequencing of 63 STRs and 95 identity SNPs, with the option to include an additional 56 ancestry SNPs and 22 phenotypic SNPs depending on the primer mix chosen for amplification, on the MiSeq desktop sequencer (Illumina). This study was divided into a series of experiments that evaluated reliability, sensitivity of detection, mixture analysis, concordance, and the ability to analyze challenged samples. Genotype accuracy, depth of coverage, and allele balance were used as informative metrics for the quality of the data produced. The ForenSeq DNA Signature Prep Kit produced reliable, reproducible results and obtained full profiles with DNA input amounts of 1 ng. Data were found to be concordant with current capillary electrophoresis methods, and mixtures at a 1:19 ratio were resolved accurately. Data from the challenged samples showed concordant results with current DNA typing methods with markers in common and minimal allele drop out from the large number of markers typed on these samples. This set of experiments indicates the beta version of the ForenSeq DNA Signature Prep Kit is a valid tool for forensic DNA typing and warrants full validation studies of this MPS technology.     

Identification and sequence analysis of discordant phenotypes between AmpFlSTR SGM Plus™ and PowerPlex® 16

During duplicate analysis of buccal swabs from 1,377 individuals with 2 commercial short tandem repeat (STR) kits, we observed 8 discordant phenotypes with SGM Plus (SGM, second generation multiplex) for the STRs THO1 (2), vWA (4) and D18S51 (2), and 1 discrepancy with PowerPlex 16 for D18S51. One individual even showed two discrepancies (vWA and THO1) for SGM Plus. In each case, the difference observed was due to the non-amplification or allele dropout of the second allele in a heterozygous genotype. Sequence analysis revealed each time the presence of a mutation that probably coincided with the primer-binding site. Primer-binding site mutations for vWA and D18S51 have been reported previously, while the mutation for THO1 (C-to-T substitution at position 1286 of GenBank sequence D00269) is reported here for the first time. While the frequency of these silent alleles remains low (0.58% in our study), it is suggested that appropriate measures should be taken for database comparisons and that allelic dropout should be further investigated by sequence analysis and be reported to the forensic community.     

Korean population genetic data and concordance for the PowerPlex® ESX 17, AmpFlSTR Identifiler®, and PowerPlex® 16 systems

In case of paternity or maternity investigations with short tandem repeat (STR) analysis, deficient cases, missing person, or mutations are encountered and common STRs cannot provide sufficient forensic parameters. Thus, it is recommended that additional STRs are needed to complement conventional analysis for more reliable forensic information. We analyzed variation of 23 STRs contained in the new PowerPlex^® ESX 17 kit (Promega) and two conventional kits of the AmpFlSTR Identifiler^® (Applied Biosystems) and PowerPlex^® 16 systems (Promega) in 452 randomly chosen individuals from Korea to provide an expanded and reliable Korean database. Allele frequencies and forensic parameters were used to evaluate suitability and robustness of the new kit for forensic genetic analysis as well as in concordance studies. The combined probability of match for the 16 loci in the PowerPlex^® ESX 17 system was 2.76 × 10⁻²⁰. One genotyping discrepancy due to a null allele was observed at the D18S51 locus (the concordant rate = 99.99%), showing a primer-binding site mutation in the sequence of the locus (G-to-A substitution at position 146 of Genbank accession number JX018211). Thus, the new kit is a valuable forensic tool and is suitable to extend the Korean population genetic data obtained with well-established polymerase chain reaction multiplex-kits of the AmpFlSTR Identifiler^® and PowerPlex^® 16 systems.     

Comprehensive mutation analysis of 17 Y-chromosomal short tandem repeat polymorphisms included in the AmpFlSTR® Yfiler® PCR amplification kit

The Y-chromosomal short tandem repeat (Y-STR) polymorphisms included in the AmpFlSTR® Yfiler® polymerase chain reaction amplification kit have become widely used for forensic and evolutionary applications where a reliable knowledge on mutation properties is necessary for correct data interpretation. Therefore, we investigated the 17 Yfiler Y-STRs in 1,730–1,764 DNA-confirmed father–son pairs per locus and found 84 sequence-confirmed mutations among the 29,792 meiotic transfers covered. Of the 84 mutations, 83 (98.8%) were single-repeat changes and one (1.2%) was a double-repeat change (ratio, 1:0.01), as well as 43 (51.2%) were repeat gains and 41 (48.8%) repeat losses (ratio, 1:0.95). Medians from Bayesian estimation of locus-specific mutation rates ranged from 0.0003 for DYS448 to 0.0074 for DYS458, with a median rate across all 17 Y-STRs of 0.0025. The mean age (at the time of son’s birth) of fathers with mutations was with 34.40 (±11.63) years higher than that of fathers without ones at 30.32 (±10.22) years, a difference that is highly statistically significant (p?<?0.001). A Poisson-based modeling revealed that the Y-STR mutation rate increased with increasing father’s age on a statistically significant level (α?=?0.0294, 2.5% quantile?=?0.0001). From combining our data with those previously published, considering all together 135,212 meiotic events and 331 mutations, we conclude for the Yfiler Y-STRs that (1) none had a mutation rate of >1%, 12 had mutation rates of >0.1% and four of <0.1%, (2) single-repeat changes were strongly favored over multiple-repeat ones for all loci but 1 and (3) considerable variation existed among loci in the ratio of repeat gains versus losses. Our finding of three Y-STR mutations in one father–son pair (and two pairs with two mutations each) has consequences for determining the threshold of allelic differences to conclude exclusion constellations in future applications of Y-STRs in paternity testing and pedigree analyses.     

Population genetic data for 15 STR loci (Identifiler™ kit) in Bolivia

Allele frequencies for 15 STR autosomal loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818 and FGA) were obtained from a sample of 200 unrelated individuals from Bolivia, South America.     

Developmental validation of the AmpFℓSTR® NGM SElect™ PCR Amplification Kit: A next-generation STR multiplex with the SE33 locus

The AmpFℓSTR^® NGM SElect™ PCR Amplification Kit is a new 17-plex STR genotyping kit designed for use primarily in forensic casework analysis. The kit was designed to be a counterpart to the AmpFℓSTR^® NGM™ Kit for laboratories wishing to add the SE33 locus to the new European Standard Set of STR loci. The NGM SElect Kit shares the same primer sets for 16 common loci with the NGM Kit (D10S1248, D3S1358, vWA, D16S539, D2S1338, amelogenin, D8S1179, D21S11, D18S51, D19S433, TH01, FGA, D22S1045, D2S441, D1S1656 and D12S391), with additional primers for the SE33 locus. Developmental validation studies followed the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines for STR kit manufacturers and tested several critical areas of kit performance including a sensitivity series, DNA mixtures and inhibited samples. The studies demonstrated that the NGM SElect Kit provides equivalent overall performance to the NGM Kit, but with even greater discriminatory power due to the inclusion of the highly informative SE33 locus.     

Population data and genetic characteristics of 12 X-STR loci using the Investigator® Argus X-12 Quality Sensor kit for the Kedayan population of Borneo in Malaysia

International Journal of Legal Medicine - DNA profiling of X-chromosomal short tandem repeats (X-STR) has exceptional value in criminal investigations, especially for complex kinship and incest...     

Forensic and population genetic analyses of Danes,Greenlanders and Somalis typed with the Yfiler® Plus PCR amplification kit

Recently, the Yfiler^® Plus PCR Amplification Kit (Yfiler^® Plus, Thermo Fisher Scientific, Waltham, MA, USA) was introduced. Yfiler^® Plus amplifies 27 Y-chromosomal short tandem repeat loci (Y-STRs) and adds ten new Y-STRs to those analysed with the commonly used AmpFlSTR^® Yfiler^® PCR Amplification Kit (Yfiler^®, Thermo Fisher Scientific, Waltham, MA, USA). Seven of the new Y-STRs are rapidly mutating Y-STRs (RM Y-STRs). In this study, 551 male individuals from Denmark, Greenland and Somalia were typed with Yfiler^® Plus. The results were compared to those obtained with Yfiler^® in the same individuals. Forensic and population genetic parameters were estimated for Yfiler^® Plus. Yfiler^® Plus had a higher power of discrimination than Yfiler^® in all three populations. Compared to Yfiler^®, Yfiler^® Plus offers increased power of discrimination, which is obviously an advantage in crime case investigations. However, the inclusion of seven RM Y-STRs in Yfiler^® Plus makes it less attractive for relationship testing because of the relatively high combined mutation rate, approximately 15%.     

The genetic structure of native Americans in North America based on the Globalfiler® STRs

Current forensic STR databases, such as CODIS, lack population genetic data on Native American populations. Information from a geographically diverse array of tribes is necessary to provide improved statistical estimates of the strength of associations with DNA evidence. The Globalfiler® STR markers were used to characterize the genetic structure of ten tribal populations from seven geographic regions in North America, including those not presently represented in forensic databases. Samples from the Arctic region, Baja California, California/Great Basin, the Southeast, Mexico, the Midwest, and the Southwest were analyzed for allele frequencies, observed and expected heterozygosities, and F-statistics. The tribal samples exhibited an F_ST or θ value above the conservative 0.03 estimate recommended by the National Research Council (NRC) for calculating random match probabilities among Native Americans. The greater differentiation among tribal populations computed here (θ = 0.04) warrants the inclusion of additional regional Native American samples into STR databases.     

High-throughput analysis using AmpFlSTR® Identifiler® with the Applied Biosystems 3500xl Genetic Analyser

High throughput analysis of buccal scrape reference samples using the Identifiler system on the Applied Biosystems 3500xl Genetic Analyser is described. This platform is much more sensitive than previous platforms, e.g. 3130xl. The range of signal detection is also much greater and this means that the system is more tolerant to a wide range of input template concentrations. DNA quantity is not a limiting factor in the analysis of buccal scrapes, hence the entire analytical procedure (process) was designed around a target input of 1.5 ng, to minimise low level DNA profiles and associated events of allele dropout. A universal stochastic threshold/limit of detection (LOD) of 300 relative fluorescent units (rfu) was applied across all loci. This level is twice that of comparable systems such as SGM Plus analysed on 3130xl instruments. After analysis of dropout probabilities, heterozygous balance, drop-in and stutter characteristics, rule-sets were programmed into the FSS i-cubed software. The process has a success rate >95%. No discordances or mis-designations occurred when applied to a validation set of more than 1000 samples.