Typical Paternity Index Research Articles

Genetic polymorphism and frequency study at 15 short tandem repeat loci in the North and East Indian populations for use in personal identification and applications in India

Allele frequency is a crucial factor in estimating the weight of evidence (WoE) for an individual’s involvement in a DNA sample. To determine the allele and genotype frequencies within the populations of the northern and eastern states of India, 15 short tandem repeats (STRs) were used, including Penta E, CSF1PO, D18S51, D7S820, D21S11, TH01, D3S1358, Vwa, FGA, TPOX, D8S1179, D16S539, D13S317, Penta D, and D5S818. The study involved 509 randomly selected individuals, analyzed using the PowerPlex 16 System Kit. Various statistical parameters of forensic significance were calculated using Forensic Statistic Analysis Toolbox (FORSTAT) software, including the typical paternity index (TPI), power of exclusion (PE), matching probability (MP), power of discrimination (PD), polymorphism information content (PIC), and observed (Hobs) and expected heterozygosities (Hexp). The analysis revealed a maximum allele frequency of 0.4282 at TPOX, with a minimum frequency of 0.0009 observed at different loci. FGA was found to be the most polymorphic loci among the 15 loci analyzed in the North and East Indian populations. Furthermore, no divergence from the Hardy‐Weinberg equilibrium (HWE) was observed. The results serve as a valuable source of information for establishing a DNA database for North and East Indian populations, providing essential information for population genetics studies and forensic casework in India.

Allelic frequencies distribution and forensic parameters of 23 autosomal short tandem repeats in the population of the State of Pernambuco, Brazil

Located in the Northeast Region, the Pernambuco State is one of the 27 federative units of Brazil. Here, we determined populational data for 23 short tandem repeat (STR) markers – CSF1PO, FGA, TH01, TPOX, vWA, D1S1656, D2S1338, D2S441, D3S1358, D5S818, D7S820, D8S1179, D10S1248, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D22S1045, PENTA D, PENTA E and SE33 — of the Pernambuco population. The sample consisted of 767 healthy, adult, unrelated individuals (437 males, 330 females) born and resident in the State of Pernambuco. STRs were amplified using three multiplex kits, according to the availability: PowerPlex® Fusion 6C System (Promega Corporation), PowerPlex® Fusion System (Promega Corporation) and GlobalFiler™ Express (Thermo Fisher Scientific). Allelic frequencies, forensic parameters and Hardy-Weinberg equilibrium determinations were estimated for all the 23 loci. No deviations from the Hardy-Weinberg equilibrium were observed for any of the markers, after Bonferroni correction. We observed that the most and less informative markers were SE33 and TPOX, respectively. The combined power of discrimination (CPD) was 0.99999999999999999999999999999, and the combined power of exclusion (CPE) was 0.99999999997. The cumulative typical paternity index was 37,919,301,869.3021. Interpopulation analyses (Nei’s genetic distance) based on the expanded CODIS core loci was performed between the Pernambuco sample and other global populations. Pernambuco was the closest Brazilian population to African group and stayed distant from the Native American group. This work contributed to show that a panel of 23 autosomal STR loci is very informative, being able for forensic applications related in this population.

Proficiency of 38 HID-INDELS in kinship analysis and forensic parameters in a Mexican population

IntroductionInsertion–deletions for human identification (HID-INDELs) allow solving peculiar forensic situations when autosomal STRs are insufficient. Although limitations were predicted since the forensic implementation of biallelic markers, formal evaluation of these restrictions is scarce. Particularly, to define the informativity provided by HID-INDELs in kinship analysis is useful to avoid wasting work, resources, and –finally– disappointments. Material and methodsFor this reason, we analyzed the 38-plex HID-INDEL system in 25 Mexican families including father, daughter, and mother, whose kinship was previously established with 22 autosomal STRs. Results and discussionFrom genotypes of unrelated individuals, we updated allele frequencies and forensic parameters of the Jalisco state (West, Mexico), by increasing the population sample size from 62 to 112. Among the forensic a priori parameters, the Typical paternity index (PI) of the 38plex HID-INDEL system showed important differences regarding the PI and probability of paternity (W) estimated herein from real paternity cases, generally undervaluing the observed informativity of these 38-plex HID-INDEL system. Conversely, the studied HID-INDEL loci offered confident kinship conclusions based on the paternity index (PI ≥10,000) and probability of paternity (W ≥ 99.99%) in 68% of the standard trio cases (18/25), and only 12% of duo paternity cases (6/50) (motherless and fatherless). In fact, 14% of duo paternity cases (7/50) did not reach minimum requirements to stablish paternity (IP < 100; W < 99%). ConclusionsWe updated a Mexican population database for 38 HID-INDEL loci, and we described their proficiency from real paternity cases, detailing some limitations non-previously specified.

Proficiency of 38 HID-INDELS in kinship analysis and forensic parameters in a Mexican population

IntroductionInsertion–deletions for human identification (HID-INDELs) allow solving peculiar forensic situations when autosomal STRs are insufficient. Although limitations were predicted since the forensic implementation of biallelic markers, formal evaluation of these restrictions is scarce. Particularly, to define the informativity provided by HID-INDELs in kinship analysis is useful to avoid wasting work, resources, and –finally– disappointments. Material and methodsFor this reason, we analyzed the 38-plex HID-INDEL system in 25 Mexican families including father, daughter, and mother, whose kinship was previously established with 22 autosomal STRs. Results and discussionFrom genotypes of unrelated individuals, we updated allele frequencies and forensic parameters of the Jalisco state (West, Mexico), by increasing the population sample size from 62 to 112. Among the forensic a priori parameters, the Typical paternity index (PI) of the 38plex HID-INDEL system showed important differences regarding the PI and probability of paternity (W) estimated herein from real paternity cases, generally undervaluing the observed informativity of these 38-plex HID-INDEL system. Conversely, the studied HID-INDEL loci offered confident kinship conclusions based on the paternity index (PI ≥10,000) and probability of paternity (W ≥ 99.99%) in 68% of the standard trio cases (18/25), and only 12% of duo paternity cases (6/50) (motherless and fatherless). In fact, 14% of duo paternity cases (7/50) did not reach minimum requirements to stablish paternity (IP < 100; W < 99%). ConclusionsWe updated a Mexican population database for 38 HID-INDEL loci, and we described their proficiency from real paternity cases, detailing some limitations non-previously specified.

Sequence-based assessment of expediency of tri-, tetra-, and penta-nucleotides repeat autosomal STR markers in the central Indian population using Next Generation Sequencing (NGS)

Present-day forensic DNA analysis is witnessing a paradigm shift from size-based allele determination by capillary electrophoresis (CE) to sequence-based allele determination by Next Generation Sequencing (NGS). An attempt has been made to evaluate the sequence-based allelic data at two tri (D12ATA63, D22S1045), two tetra (D18S51, D1S1656), and two penta- (Penta D, Penta E) nucleotides repeat STR markers in the central Indian population. 183.33 times allele gain has been observed in D1S1656 after evaluating individual allelic sequences in comparison to the size-based alleles. Despite not witnessing any sequence-based allele gain, highest power of discrimination (0.978), Polymorphic Information Content (0.9), Power of Exclusion (0.807), typical paternity index (5.31), Expected heterozygosity (0.906), and lowest matching probability (0.022) was observed at Penta E marker suggesting its more usefulness among the considered markers for forensic and paternity applications. A giant leap in sequence-based allelic information showed a significant increase in forensic and paternity parameters (p = 0.646) in D1S1656. Substitution of TAGA with either TAGG or TAGC was found to be responsible for the generation of sequence variant alleles in D1S1656. Besides, the observation of rs4847015 SNP in 11.5% of sequences further increases the evidentiary value of D1S1656 in comparison to other STR markers analyzed in this study.

Genetic polymorphism and phylogenetic analysis of 15 autosomal STR markers in the Santal indigenous population of Bangladesh

Fifteen autosomal STR markers, namely D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA were typed using AmpFlSTR® Identifiler® Plus PCR amplification systems in 132 unrelated Santal individuals of Bangladesh. Forensic efficiency parameters like, matching probability (MP), power of discrimination (PD), polymorphism information content (PIC), power of exclusion (PE), typical paternity index (TPI), observed heterozygosity (Hobs), and expected heterozygosity (Hexp) were calculated for all the loci. No deviations from Hardy-Weinberg equilibrium were detected for the loci after Bonferroni correction. The combined matching probability (MP), combined power of discrimination (PD) and combined power of exclusion (PE) for the 15 tested STR markers were 8.38 x 10-17, 0.999999998 and 0.0.999993866, respectively. A comparison of the locus wise allele frequencies of autosomal STR data of the Santal population with the published geographically close population data based on Nei’s genetic distance revealed that the Santal population is closely related to Munda population from Jharkhand, India.&#x0D; Bioresearch Commu. 7(2): 1004-1009, 2021 (June)

Massively parallel sequencing of 25 short tandem repeat loci including the SE33 marker in Koreans.

Massively parallel sequencing (MPS) technology has recently been introduced in research, clinical diagnostics, and forensics. MPS enables determination of the genotypes of multiple short tandem repeat (STR) markers and to determine nucleotide sequence variations, additionally. To improve STR analysis and a paternity index, a new, smaller-sized STR panel was designed that includes the SE33 locus. This study performed MPS using an STR panel including the SE33 marker in 101 Koreans. The concordance study was conducted by comparing the data obtained from the MPS assay with the results of a capillary electrophoresis (CE)-based method. In this study, an in-house MPS panel is designed that incorporates the 20 Combined DNA Index System (CODIS) loci and the Penta D, Penta E, and SE33 markers for enhanced discriminatory ability. The data obtained via MPS analysis were compared with CE data to confirm concordance. Fifty previously unreported alleles were detected through the MPS analysis. Three new SNP variations in the flanking region were also identified. Statistical analysis demonstrated that the SE33 marker was most effectively determined the match probability (PM) and typical paternity index (TPI). In the sensitivity study, concentrations as low as 80pg could be used to obtain full and concordant profiles. We designed a new, smaller-sized STR panel that includes the SE33 locus to improve STR analysis and the paternity index. Various new alleles were identified in SE33, indicating a high degree of polymorphism. The panel is expected to provide valid data for discrimination of unidentified bodies.

Sequencing of human identification markers in an Uyghur population using the MiSeq FGxTM Forensic Genomics System

Massively parallel sequencing (MPS) offers a useful alternative to capillary electrophoresis (CE) based analysis of human identification markers in forensic genetics. By sequencing short tandem repeats (STRs) instead of determining the fragment lengths by CE, the sequence variation within the repeat region and the flanking regions may be identified. In this study, we typed 264 Uyghur individuals using the MiSeq FGx™ Forensic Genomics System and Primer Mix A of the ForenSeq™ DNA Signature Prep Kit that amplifies 27 autosomal STRs, 25 Y-STRs, seven X-STRs, and 94 HID-SNPs. STRinNGS v.1.0 and GATK 3.6 were used to analyze the STR regions and HID-SNPs, respectively. Increased allelic diversity was observed for 33 STRs with the PCR-MPS assay. The largest increases were found in DYS389II and D12S391, where the numbers of sequenced alleles were 3–4 times larger than those of alleles determined by repeat length alone. A relatively large number of flanking region variants (28 SNPs and three InDels) were observed in the Uyghur population. Seventeen of the flanking region SNPs were rare, and 12 of these SNPs had no accession number in dbSNP. The combined mean match probability and typical paternity index based on 26 sequenced autosomal STRs were 3.85E−36 and 1.49E + 16, respectively. This was 10 000 times lower and 1 000 times higher, respectively, than the same parameters calculated from STR repeat lengths. Highlights Sequencing data on STRs and SNPs used for human identification are presented for the Uyghur population. STRinNGS v.1.0 was used to analyze the flanking regions of STRs. The concordance between PCR-CE and PCR-MPS results was 99.86%. Detection of sequence variation in STRs and their flanking regions increased the allelic diversity.

A genomic exploration of 15 autosomal STR loci for establishment of a DNA profile database of the population of Himachal Pradesh.

In order to create an autosomal STR loci population database for Himachal Pradesh, 259 blood samples were taken from people residing in various regions of the state and AmpFlSTR® Identifiler® Plus PCR amplification kit was used for evaluation of 15 autosomal STR markers. A total of 149 alleles were investigated in this study with a mean allele number of 9.933 per locus. The locus D2S1338 was most informative in our data, as it had the highest discrimination power (PD-0.967) and the highest polymorphic information content (PIC-0.86). The matching probability and typical paternity index for all the studied loci were observed as 2.9x10-18 and 4.7x105, respectively. Discrimination power (CPD) and exclusion power (CPE) for all the studied loci were observed as 1 and 0.999998.

Expediency of Tetra- and Pentanucleotide Repeat Autosomal STR Markers for DNA Typing in Central Indian Population

The STR typing has been regarded as the most reliable and robust genetic tool having a pivotal role in the criminal justice system. High mutation rates have led to widespread polymorphism in the STRs which increases the probability of divergence of a specific population. Therefore, two tetra- and two pentanucleotide repeat STR loci were evaluated for their informativeness and expediency in the central Indian population. Two hundred unrelated individuals of the central India were included in this study for DNA isolation followed by multiplex PCR and genotyping using four STR markers, i.e., D2S1338, D19S433, Penta E and Penta D. All STR markers followed the Hardy–Weinberg equilibrium in the studied population. Out of all, Penta E (15p15-39; AAAGA) was found to be the most polymorphic (25–120 bp), highest heterozygosity (92.0%), lowest matching probability (0.025), highest power of discrimination (0.975), polymorphic information content (PIC) (0.91), power of exclusion (0.936) and typical paternity index (6.25). The aptness of the Penta E STR marker in context to its forensic and paternity parameters strongly suggests its applicability in the central Indian population.

Study of insertion-deletion polymorphisms (indels) in the UAE population

Insertion-deletion polymorphisms (indels) have been used less in forensic identification of individuals in comparison to short tandem repeat (STR) and single nucleotide polymorphism (SNP) systems. The use of indels has many advantages including low costs, simple typing methods as well as a small amplicon size of under 160 bp making them suitable for genotyping highly degraded DNA. They can also be valuable as a complementary tool to help resolve kinship cases, with the advantage of lower mutation rates when compared to STRs. The main objective of this study was to investigate the polymorphism of 30 indel loci in the UAE population and to evaluate its suitability for forensic applications. The Qiagen Investigator® DIPplex kit was used to amplify 30 biallellic indel loci and the amelogenin locus in 500 blood samples. This technique was robust, relatively simple, and the results were analysed using the same capillary electrophoresis equipment and software used for STR typing. Allele frequencies were evaluated and forensic parameters (match probability, power of discrimination, polymorphism information content, power of exclusion and typical paternity index) were estimated for the 30 autosomal indel loci. No significant departure from Hardy-Weinberg equilibrium (HWE) expectations were observed for most of the indel loci analyzed in the samples obtained from the UAE population. The combined power of discrimination (CPD) and combined match probability (CMP) values were 0.999999999999754 and 2.46 × 10−13, respectively, which indicated that the 30 indel loci are highly polymorphic and are appropriate for forensic human identification purposes. Even when the match probability of STRs was low, indels gave an acceptable value for forensic application.

Allele frequency data for 15 autosomal strs and ancestral proportions using aims-indels in the shuar ethnic group from Ecuador

The ethnic group Shuar is located in Ecuador. To identify their genetic composition, 46 ancestry-informative insertion deletion markers (AIM-INDELs) were used. Also, characterization of 15 tandem repeats (STRs) in the AmpFISTR Identifiler Kit were applied. Forensic parameters showed a matching probability of 0.1535, a power of discrimination of 0.8465, a polymorphism information content of 0.6584, probability of exclusion of 0.415 and a typical paternity index of 1.78. The Shuar are not influenced by admixture population events, being a Native American group 98.7%, along with a genetic diversity of 0.699346+/-0.356964.

Non-invasive prenatal paternity testing using a standard forensic genetic massively parallel sequencing assay for amplification of human identification SNPs.

Prenatal paternity testing often relies on invasive procedures that cause risk to both the mother and the foetus. Non-invasive, prenatal paternity testing by investigating paternally inherited single nucleotide polymorphisms (SNPs) in cell-free foetal DNA (cffDNA) in maternal plasma was performed at consecutive time points during early gestation. Plasma from 15 pregnant women was investigated at consecutive time points from gestational weeks (GWs) 4-20. The Precision ID Identity Panel and an Ion S5 Sequencer was used to analyse the cffDNA. Paternally inherited foetal SNP alleles were detected from GW7. The median foetal fractions were 0%, 3.9%, 5.1%, 5.2%, and 4.7% at GWs 4, 7, 12, 16, and 20, respectively. The corresponding median numbers of detected paternally inherited foetal autosomal SNP alleles were 0, 3, 9, 10, and 12, respectively. The typical (i.e. geometric mean) paternity indices at GW12 and GW20 were 24 (range 0.0035-8389) and 199 (range 5.1-30,137), respectively. The method is very promising. However, the method can be improved by shortening the lengths of the PCR amplicons and increasing the number of SNPs. To our knowledge, this is the first study to successfully identify paternally inherited foetal SNP alleles at consecutive time points in early gestation independently of the foetal gender.

Massively parallel sequence data of 31 autosomal STR loci from 496 Spanish individuals revealed concordance with CE-STR technology and enhanced discrimination power

This study reports Short Tandem Repeat (STR) sequence-based allele data from 496 Spanish individuals across 31 autosomal STR (auSTR) loci included in the Precision ID GlobalFiler™ NGS STR Panel v2: D12S391, D13S317, D8S1179, D21S11, D3S1358, D5S818, D1S1656, D2S1338, vWA, D2S441, D5S2800, D7S820, D16S539, D6S474, D12ATA63, D4S2408, D6S1043, D19S433, D14S1434, CSF1PO, D10S1248, D18S51, D1S1677, D22S1045, D2S1776, D3S4529, FGA, Penta D, Penta E, TH01 and TPOX. The sequence of each allele was aligned to the reference sequence GRCh37 (hg19) and formatted according to the guidance of the International Society for Forensic Genetics. A subset of 221 samples was evaluated for testing concordance with allele calls derived from CE-based analysis using PowerPlex Fusion 6C, and there was 99.95% allele concordance. Twenty-five out of 31 auSTR loci showed an increased number of alleles due to repeat region sequence variation and/or single nucleotide polymorphisms (SNP) residing in the flanking regions. A total of 18 loci showed increased observed heterozygosity due to sequence variation; the loci exhibiting the greatest increase were: D13S317 (12% points), D5S818 (10% points), D8S1179 (7% points), D3S1358 (7% points), and D21S11 (6% points). The combined match probability decreased from 2.022E-24 (length-based data) to 1.042E-27 (sequence-based data) for the 20 CODIS core STR loci. The combined match probability (sequence-based data) for the 31 STR loci studied was 4.777E-40. The combined typical paternity index increased from 1.118E + 12 to 8.179E + 13 using length and sequence-based data, respectively. This Spanish population study performed in the framework of the EU-funded DNASEQEX project is expected to provide STR sequence-based allele frequencies for forensic casework and support implementation of massively parallel sequencing (MPS) technology in forensic laboratories.

Genetic characterization of 21 autosomal STR loci of Goldeneye™ DNA ID 22NC Kit in Chinese She group.

Genetic polymorphism of 21 autosomal STR loci included in Goldeneye™ DNA ID 22NC Kit (D19S253, D6S477, D22GATA198B05, D15S659, D8S1132, D3S1358, D3S3045, D14S608, D17S1290, D3S1744, D2S411, D18S535, D13S325, D7S1517, D10S1435, D11S2368, D4S2366, D1S1656, D7S3048, D10S1248 and D5S2500) was studied in 297 unrelated She individuals. Allele frequencies and forensic efficiency parameters such as, observed and expected heterozygosity (Ho & He), matching probability (MP), power of discrimination (PD), polymorphism information content (PIC), power of exclusion (PE), typical paternity index (TPI) was calculated for the loci. The combined PD and PE for all 21 STR loci were calculated to be 0.999999999999999999999999324094 and 0.999999996182425, respectively. The dataset indicated the usefulness of these loci in personal identification, parentage testing and complex kinship analysis in She population. The MDS plots and neighbor-joining tree were constructed based on pair-wise Nei's genetic distance by comparing allele frequency data for the 21 loci with ten other populations. The analysis showed that She population lies closer to a clade consisting Southern Han, Hainan Han and Li populations.

The Danish STR sequence database: duplicate typing of 363 Danes with the ForenSeq™ DNA Signature Prep Kit.

Some STR loci have internal sequence variations, which are not revealed by the standard STR typing methods used in forensic genetics (PCR and fragment length analysis by capillary electrophoresis (CE)). Typing of STRs with next-generation sequencing (NGS) uncovers the sequence variation in the repeat region and in the flanking regions. In this study, 363 Danish individuals were typed for 56 STRs (26 autosomal STRs, 24 Y-STRs, and 6 X-STRs) using the ForenSeq™ DNA Signature Prep Kit to establish a Danish STR sequence database. Increased allelic diversity was observed in 34 STRs by the PCR-NGS assay. The largest increases were found in DYS389II and D12S391, where the numbers of sequenced alleles were around four times larger than the numbers of alleles determined by repeat length alone. Thirteen SNPs and one InDel were identified in the flanking regions of 12 STRs. Furthermore, 36 single positions and five longer stretches in the STR flanking regions were found to have dubious genotyping quality. The combined match probability of the 26 autosomal STRs was 10,000 times larger using the PCR-NGS assay than by using PCR-CE. The typical paternity indices for trios and duos were 500 and 100 times larger, respectively, than those obtained with PCR-CE. The assay also amplified 94 SNPs selected for human identification. Eleven of these loci were not in Hardy-Weinberg equilibrium in the Danish population, most likely because the minimum threshold for allele calling (30 reads) in the ForenSeq™ Universal Analysis Software was too low and frequent allele dropouts were not detected.

Genetic analysis of old skeletal remains from Korean War victims using PowerPlex® Fusion 6C and MiniSTR system for human identification

To analyze and identify the population of the Korean War victims by studying degraded old bones based genetic analysis, we examined 108 unrelated individual femurs except two low quality bones from total investigated 110 samples. In order to obtain significantly improved genetic profiles, amplification was performed using recently developed commercial PowerPlex® Fusion 6C system and miniSTR system. We have modified PCR condition to gain enhanced DNA profiling at a success rate. When each value of two different systems came out respectively as 92.35% and 91.05% only, it created 4.40% increased value which rated at 95.45% by using these two systems simultaneously. Especially, 100% showed at D1S1656, D2S441 and D12S391, which overlapped with miniSTR system. Total of 24 autosomal STRs had gene diversity values from 0.7751 to 0.9934; SE33, Penta E, and D2S1338 which were the best in that order. The most frequent value was 0.5170 at TPOX(8) in the frequencies ranging from 6 to 37 allele. Polymorphism information content, power of discrimination and exclusion, typical paternity index and heterozygote were the highest value at SE33, but TPOX appeared the lowest in all statistics. However the value of matching probability and homozygote showed the opposite result. Since above data anticipate that these outcomes confirm the similar patterns compared to previous reported Korean population papers, it verifies the population based genetic analysis using advanced these two systems is very helpful to increase an efficiency as well as a higher accuracy on identification of victims and also to check of identical samples.

Genetic polymorphism studies on 22 autosomal STR loci of the PowerPlex Fusion System in Bangladeshi population.

Genetic polymorphism of 22 autosomal STR loci included in PowerPlex® Fusion System (D3S1358, D1S1656, D2S441, D10S1248, D13S317, Penta E, D16S539, D18S51, D2S1338, CSF1PO, Penta D, TH01, vWA, D21S11, D7S820, D5S818, TPOX, D8S1179, D12S391, D19S433, FGA and D22S1045) was studied in 188 unrelated Bangladeshi Bengali individuals. Allele frequencies and forensic efficiency parameters such as, the power of discrimination (PD), observed and expected heterozygosity (Ho & He), polymorphism information content (PIC), probability of match (PM), power of exclusion (PE) and typical paternity index was calculated for the loci. The combined PM and PE for all 22 STR loci were calculated to be 5.29×10-27 and 0.99999999945 respectively. The dataset indicated the usefulness of these loci in personal identification, parentage testing and complex kinship analysis in Bangladeshi population. A neighbor-joining tree was constructed based on pair-wise Nei's genetic distance by comparing allele frequency data for the 22 loci with six other populations. The analysis showed that Bangladeshi population lies closer to a clade consisting Japan, the Philippines and East Timot populations.

Forensic parameters of the Powerplex® 21 system (Promega Corp.) in mestizo populations from the West of Mexico

IntroductionMicrosatellites or short tandem repeats (STR) are the markers of choice in human identification. For this purpose, they must be analyzed in populations. This task has been scarcely performed for new generation human identification systems, which is critical in Mexican mestizo populations, because a significant genetic structure has been demonstrated due to admixture differences. ObjectiveTo validate the system in mestizo populations from the west region of Mexico. MethodsA total of 374 unrelated Mexican-mestizos from the west region were analyzed with the Powerplex® 21 system. Genetic data were analyzed using different softwares and including additional related populations for comparison purposes. Results and conclusionsWe estimated allele frequencies, and genotype distribution of all markers was in agreement with Hardy-Weinberg expectations; the linkage disequilibrium test discarded association between all pair of loci. The following forensic parameters were estimated: power of discrimination (PD), power of exclusion (PE), heterozygosity (Het), polymorphism information content (PIC), and typical paternity index (PI); its combined power of discrimination and exclusion was –100% and 99.999999473%, respectively. This constitutes an important increment with respect to typical 15 STR systems for the same population/region. This report validates the Powerplex® 21 system in western Mexican-mestizos for confident interpretation of DNA profiles in forensic cases and paternity testing. Sistema Powerplex® 21; México; Identificación humana; Poblaciones.

Population data for SE33 locus in United Arab Emirates Arab population

The high power of discrimination for SE33 locus makes it one of the most informative loci for forensic applications. Considering that locus finding its way to most of the new commercially available autosomal STR multiplexes assays, it is important to evaluate forensic parameters in UAE population before implementing kits including such locus. Here we present a genetic population study for SE33 locus in the United Arab Emirates (UAE) Arab population. 588 randomly collected samples were amplified using optimized in-house singleplex reaction. Forensic parameters including matching probability, power of discrimination, paternity power of exclusion and typical paternity index were calculated using Arlequin v3.5 software. Results demonstrate SE33 competence in UAE population as same as in other populations. In comparison with previously published data of 15 autosomal STR loci for UAE population [1], SE33 locus was found to have the highest power of discrimination and therefore it demonstrates the potential usefulness for forensic applications in caseworks as well as in complex paternity cases.