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Abstract Tandem repeat genetic profiles used in forensic applications varies between populations. Despite the diversity and security issues in the Sahel that require the identification of victims (soldiers and civilians), Burkina Faso (BF) remains understudied. To fill this information gap, 396 unrelated individuals from BF were genotyped using a MICROREADER 21 ID System kit. All 20 short tandem repeat (STR) loci tested passed the Hardy–Weinberg equilibrium (HWE) test. The combined powers of exclusion for duos (CPE duos) and trios (CPE trios) for the 20 tested loci were 0.9999998 and 0.9999307, respectively. The probability that two individuals would share the same DNA profiles among the BF population was 9.80898 × 10–26. For the X-chromosome STR analysis, 292 individuals were included in this study using a MICROREADER 19X Direct ID System kit. Among the 19 loci, no significant deviations from HWE test were observed in female samples after Bonferroni correction (p

In this study, 241 mixed autosomal STR genetic profiles (swabs − 172, slides − 69) from processed casework samples were analysed. From these samples, DNA was extracted and quantified by qPCR; the results were analysed with the PowerQuant Analysis Software. The extracted DNA samples were amplified with the Investigator 24Plex QS and VeriFiler kits and separated and detected in an ABI 3500 Genetic Analyzer. A quantification correlation was observed between the total autosomal DNA targets [Auto] and the Y chromosome target [Y] in mixed samples in which the success of amplification of the male autosomal STRs markers was associated with high values of the quantification of the target of [Y] and low DNA ratio values [Auto]/[Y] (p = 0.00 < 0.05). Samples with [Auto]/[Y] ratio values much higher than the estimated value required analysis with Y-STR markers. The study herein, which assessed a relatively large number of sexual assault samples, demonstrates that quantitation ratio values of DNA mixtures effectively contribute to the decision-making process on whether and what genetic marker system should be selected for analysis of a male component in unknown casework samples. [ABSTRACT FROM AUTHOR]

The Xinjiang Uyghur Autonomous Region of China (XUARC) harbors almost 50 ethnic groups including the Uyghur (UGR: 45.84%), Han (HAN: 40.48%), Kazakh (KZK: 6.50%), Hui (HUI: 4.51%), Kyrgyz (KGZ: 0.86%), Mongol (MGL: 0.81%), Manchu (MCH: 0.11%), and Uzbek (UZK: 0.066%), which make it one of the most colorful regions with abundant cultural and genetic diversities. In our previous study, we established allelic frequency databases for 14 autosomal short tandem repeats (STRs) for four minority populations from XUARC (MCH, KGZ, MGL, and UZK) using the AmpFlSTR® Identifiler PCR Amplification Kit. In this study, we genotyped 2,121 samples using the GoldenEye™ 20A Kit (Beijing PeopleSpot Inc., Beijing, China) amplifying 19 autosomal STR loci for four major ethnic groups (UGR, HAN, KZK, and HUI). These groups make up 97.33% of the total XUARC population. The total number of alleles for all the 19 STRs in these populations ranged from 232 (HAN) to 224 (KZK). We did not observe any departures from the Hardy-Weinberg equilibrium (HWE) in these populations after sequential Bonferroni correction. We did find minimal departure from linkage equilibrium (LE) for a small number of pairwise combinations of loci. The match probabilities for the different populations ranged from 1 in 1.66 × 1023 (HAN) to 6.05 × 1024 (HUI), the combined power of exclusion ranged from 0.999 999 988 (HUI) to 0.999 999 993 (UGR), and the combined power of discrimination ranged from 0.999 999 999 999 999 999 999 983 (HAN) to 0.999 999 999 999 999 999 999 997 (UGR). Genetic distances, principal component analysis (PCA), STRUCTURE analysis, and the phylogenetic tree showed that genetic affinity among studied populations is consistent with linguistic, ethnic, and geographical classifications. [ABSTRACT FROM AUTHOR]

Tandem repeat genetic profiles used in forensic applications varies between populations. Despite the diversity and security issues in the Sahel that require the identification of victims (soldiers and civilians), Burkina Faso (BF) remains understudied. To fill this information gap, 396 unrelated individuals from BF were genotyped using a MICROREADER 21 ID System kit. All 20 short tandem repeat (STR) loci tested passed the Hardy–Weinberg equilibrium (HWE) test. The combined powers of exclusion for duos (CPE duos) and trios (CPE trios) for the 20 tested loci were 0.9999998 and 0.9999307, respectively. The probability that two individuals would share the same DNA profiles among the BF population was 9.80898 × 10–26. For the X-chromosome STR analysis, 292 individuals were included in this study using a MICROREADER 19X Direct ID System kit. Among the 19 loci, no significant deviations from HWE test were observed in female samples after Bonferroni correction (p < 0.05/19 = 0.0026), except for loci GATA165B12 and DXS7423. The results showed that the combined power of exclusion (CPE) and the combined power of discrimination in females (CPDF) and males (CPDM) were 0.999999760893, 0.999999999992, and 1, respectively. Comparison with other African sub-populations showed that geographical proximity is a reliable indicator of genetic relatedness. [ABSTRACT FROM AUTHOR]

The present study aimed to establish human earwax as a potential source of DNA evidence that could be effectively used in human identification. Sixty earwax samples were obtained from 15 healthy male and female Saudi volunteers living in Riyadh, Saudi Arabia. Four consecutive earwax swab samples were obtained from each volunteer and stored for 1, 15, 30 and 60 days. Earwax samples were stored at room temperature (20–22 °C). Reference oral swab was also taken from each volunteer. DNA was extracted by QIAamp DNA Mini kit and quantified by real-time polymerase chain reaction (RT-PCR) on 7500 Thermal Cycler. Autosomal STR loci were amplified using AmpFLSTR™ Identifiler™ Plus PCR Amplification Kit (Thermo Fisher Scientific, Carlsbad, CA, USA). Amplified fragments were size separated and analyzed on a 3500 Genetic Analyzer. Complete autosomal STR profiles were obtained from the earwax swabs of all the volunteers stored up to 30 days after the collection. Some STR profiles were partially obtained 60 days after the earwax collection. Allelic drop-out, allelic drop-in, and stutters were seen in earwax samples analyzed 60 days after the collection. The results have shown that human earwax can be a potential source of DNA evidence for human identification up to 30 days after the earwax collection. It is recommended to quickly analyze earwax samples or store them at room temperature or at −10 °C after their recovery from the crime scene.

The former Kingdom of Granada, comprising the provinces of Granada, Málaga, and Almería (GMA), was once inhabited for over 700 years (711–1492 AD) by a North African population, which influenced its creation and establishment. The genetic data on 15 autosomal short tandem repeats (STRs) in 245 unrelated donor residents were examined in order to assess any possible admixture. As the two surnames in Spain follow an inheritance similar to the Y chromosome, both surnames of all 245 unrelated individuals were queried and annotated. The Spanish Statistics Office website was consulted to determine the regions with the highest frequency of individuals born bearing each surname. Further, several heraldry and lineage pages were examined to determine the historical origin of the surnames. By AMOVA and STRUCTURE analysis, the populations of the three provinces can be treated genetically as a single population. The analysis of allele frequencies and genetic distance demonstrated that the GMA population lay in the Spanish population group but was slightly more similar to the North African populations than the remainder of the Spanish populations. In addition, the surnames of most individuals originated in Northern and Central Spain, whereas most surnames had higher frequencies in Southern Spain. These results confirm that the GMA population shows no characteristics that reflect a greater genetic influence of North African people than the rest of the populations of the Iberian Peninsula. This feature is consistent with the historical data that African inhabitants were expelled or isolated during the repopulation of the region with Spaniards from Northern Spain. The knowledge of present populations and their genetic history is essential for better statistical results in kinship analyses. [ABSTRACT FROM AUTHOR]

Background STR (Short Tandem Repeat) markers are highly polymorphic markers, which are widely used in forensics DNA analysis and aid to ascertain unique genotype profiles of individuals and determine the genetic diversity of the given population. Aim In the present study, an attempt has been made to evaluate the population genetic diversity of the Ramgharia Sikh population of Punjab, India, using 21 autosomal STR loci (D3S1358, vWA, D16S539, CSF1PO, TPOX, D8S1179, D21S11, D18S51, D2S441, D19S433, TH01, FGA, D22S1045, D5S818, D13S317, D7S820, SE33, D10S1248, D1S1656, D12S391, and D2S1338) to augment the emerging forensic database related to the indigenous population of India. Subjects and methods For generation of the database, 200 (blood on FTA card) samples were obtained from genetically unrelated Ramgharia Sikhs residing in the state of Punjab. Twenty-one autosomal STR markers were analysed using the Globalfiler® PCR amplification kit. Results With the help of various statistical tools, a total of 232 alleles were observed and 11.048 ± 1.284 (mean ± standard deviation) alleles per locus were recorded. No locus deviated from Hardy Weinberg Equilibrium. SE33 locus was found to be the most polymorphic and exhibited the highest discrimination power, that is, 0.99. Moreover, results further indicated that Ramgharia Sikhs of Punjab showed a high affinity with Bhils of Madhya Pradesh (India). Thus, the studied population showed genetic proximity with the geographically close populations of India and showed significant genetic variations with distant populations, which was evident from the UPGMA tree and Principal Component Analysis plot. Conclusion Overall, the 21 autosomal STRs were found to be polymorphic in the Ramgharia population and suitable for forensic casework and studies on population genetics.

Aim The present study was designed to explore the STR diversity and genomic history of the inhabitants of the most populous subdivision of the country. A set of 24 hypervariable autosomal STRs was used to estimate the genetic diversity within the studied population. A panel of 15 autosomal STRs, which is most common in the previously reported data sets, was used to estimate the genetic diversity between the studied population, and obtained unique relations were reported here. Method The genetic diversity and polymorphism among 636 individuals of different ethnic groups, residing in Bareilly, Pilibhit, Shahjahanpur, Gorakhpur, Jhansi, and Varanasi regions of Uttar Pradesh, India, was investigated. This investigation was carried out via 24 autosomal STRs. Result The 24 loci studied showed the highest value of combined power of discrimination (CPD = 1), combined power of exclusion (CPE = 0.99999999985), combined paternity index (CPI = 6.10 × 109) and lowest combined matching probability (CPM = 7.90 × 10−31). Conclusion The studied population showed genetic closeness with the population of Uttarakhand, the Jats of Delhi,the Jat Sikh (Punjab), and the population of Rajasthan. Among the tested loci, SE33 and Penta E were found to be most useful in terms of the highest discrimination power, lowest matching probability, the highest power of exclusion, and highest polymorphism information content for the Uttar Pradesh population .

Nigeria is the most populous African nation, comprising over 250 ethnic groups. The Yoruba and Fulani are the second and fourth largest ethnic groups in Nigeria, respectively. Forensic genotyping of short tandem repeats (STRs) is used in computation of Combined DNA Index System databases of individuals and ethnic groups. We examined allele diversity, haplotype frequency, haplotype diversity, and forensic genotyping data of autosomal STRs in Fulani and Yoruba residents in Ilorin, Kwara State, North Central Nigeria, in-order to further provide forensic genotyping data of these ethnic groups. Samples of 25 Fulani males and 23 Yoruba males whose ethnicity was confirmed by three generations (paternal and maternal) were collected with informed consent using purposive sampling. All individuals in the samples were unrelated. The samples were amplified and then genotyped using the SureID® 21G PCR Amplification Kit containing Amelogenin and 20 autosomal STR loci. Statistical analyses of forensic genotyping parameters confirmed no deviation from expectation of Hardy-Weinberg Equilibrium and no dependence of alleles between loci. All tested loci were polymorphic. Expected Heterozygosity and gene diversity parameters showed lower genetic diversity amongst Fulanis compared to Yorubas. This is possibly due to the prevalent custom of marriage between cousins amongst Fulanis, which is forbidden in Yoruba customs.

Background Due to its strategic location, Tunisia witnessed the succession and influence of many civilisations throughout history. However, the majority of studies carried out on Tunisia are focussed on Barbarian ethnicity. Aim To estimate genetic diversity and genetic structure of three Tunisian populations using autosomal STRs. Subjects and methods 278 individuals were analysed for sixteen STRs. Allele frequencies and statistical parameters were determined. Results The studied populations showed genetic affinity with geographically close populations. AMOVA showed no genetic difference between the Tunisian populations. Nevertheless, the variance between the populations of the same group was significant, reflecting their heterogeneity even though they came from the same geographical area, and had the same ethnicity and complex demographic history. Conclusion Our results strongly supported the application of autosomal genetic markers in anthropological and forensic studies. The analyses conducted at the 15-loci level provide the resolution to assess the phylogenetic relationships among the populations examined and other geographically targeted worldwide populations, while the results resulting from the 10-loci studies provide an understanding of the relationships and origins of the North African populations. Furthermore, the current report demonstrates that the battery of autosomal STRs reported are useful, providing the power of discrimination for forensic and paternity analyses.

STR (Short Tandem Repeat) markers are highly polymorphic markers, which are widely used in forensics DNA analysis and aid to ascertain unique genotype profiles of individuals and determine the genetic diversity of the given population. In the present study, an attempt has been made to evaluate the population genetic diversity of the Ramgharia Sikh population of Punjab, India, using 21 autosomal STR loci (D3S1358, vWA, D16S539, CSF1PO, TPOX, D8S1179, D21S11, D18S51, D2S441, D19S433, TH01, FGA, D22S1045, D5S818, D13S317, D7S820, SE33, D10S1248, D1S1656, D12S391, and D2S1338) to augment the emerging forensic database related to the indigenous population of India. For generation of the database, 200 (blood on FTA card) samples were obtained from genetically unrelated Ramgharia Sikhs residing in the state of Punjab. Twenty-one autosomal STR markers were analysed using the Globalfiler® PCR amplification kit. With the help of various statistical tools, a total of 232 alleles were observed and 11.048 ± 1.284 (mean ± standard deviation) alleles per locus were recorded. No locus deviated from Hardy Weinberg Equilibrium. SE33 locus was found to be the most polymorphic and exhibited the highest discrimination power, that is, 0.99. Moreover, results further indicated that Ramgharia Sikhs of Punjab showed a high affinity with Bhils of Madhya Pradesh (India). Thus, the studied population showed genetic proximity with the geographically close populations of India and showed significant genetic variations with distant populations, which was evident from the UPGMA tree and Principal Component Analysis plot. Overall, the 21 autosomal STRs were found to be polymorphic in the Ramgharia population and suitable for forensic casework and studies on population genetics. [ABSTRACT FROM AUTHOR]

Short tandem repeats (STRs) play an essential role in forensic genetics due to their high degree of polymorphisms, wide distributions and easy detection method. In this study, allelic frequencies and forensic statistical parameters of the 19 autosomal STR loci in a Kazak ethnic group were calculated, and its genetic relationships with reference populations were assessed in order to understand population structure better and enrich population genetic data for forensic practice in Chinese Kazak ethnic group. There were 226 identified alleles with the corresponding allelic frequencies ranging from 0.0008 to 0.5295 in the 628 unrelated healthy Kazak individuals in Xinjiang Uygur Autonomous Region. All autosomal STRs were conformed to the Hardy-Weinberg equilibrium after Bonferroni's correction. The cumulative power of discrimination and the combined probability of exclusion of all the 19 autosomal STRs were 0.999 999 999 999 999 999 999 997 162 and 0.999 999 994 484, respectively. Furthermore, the DA distances and Fixation index values of pairwise populations, principal component analysis, multidimensional scaling analysis, phylogenetic tree analysis and structure analysis were conducted to probe the genetic relationships between the Kazak group and other reference populations. The population genetic results showed that these 19 autosomal STR loci were characterised by high genetic diversities in the Kazak group. Furthermore, the studied Kazak group had close genetic relationships with the Uyghur group and the Uzbek group. The present results may facilitate understanding the genetic background of the Chinese Xinjiang Kazak group. [ABSTRACT FROM AUTHOR]

In recent years, probabilistic genotyping software has been adapted for the analysis of massively parallel sequencing (MPS) forensic data. Likelihood ratios (LR) are based on allele frequencies selected from populations of interest. This study provides an outline of sequence-based (SB) allele frequencies for autosomal short tandem repeats (aSTRs) and identity single nucleotide polymorphisms (iSNPs) in 371 individuals from Southern Norway. 27 aSTRs and 94 iSNPs were previously analysed with the ForenSeq™ DNA Signature Prep Kit (Verogen). The number of alleles with frequencies less than 0.05 for sequenced-based alleles was 4.6 times higher than for length-based alleles. Consistent with previous studies, it was observed that sequence-based data (both with and without flanks) exhibited higher allele diversity compared to length-based (LB) data; random match probabilities were lower for SB alleles confirming their advantage to discriminate between individuals. Two alleles in markers D22S1045 and Penta D were observed with SNPs in the 3´ flanking region, which have not been reported before. Also, a novel SNP with a minor allele frequency (MAF) of 0.001, was found in marker TH01. The impact of the sample size on minor allele frequency (MAF) values was studied in 88 iSNPs from Southern Norway (n = 371). The findings were then compared to a larger Norwegian population dataset (n = 15,769). The results showed that the smaller Southern Norway dataset provided similar results, and it was a representative sample. Population structure was analyzed for regions within Southern Norway; F ST estimates for aSTR and iSNPs did not indicate any genetic structure. Finally, we investigated the genetic differences between Southern Norway and two other populations: Northern Norway and Denmark. Allele frequencies between these populations were compared, and we found no significant frequency differences (p-values > 0.0001). We also calculated the pairwise F ST values per marker and comparisons between Southern and Northern Norway showed small differences. In contrast, the comparisons between Southern Norway and Denmark showed higher F ST values for some markers, possibly driven by distinct alleles that were present in only one of the populations. In summary, we propose that allele frequencies from each population considered in this study could be used interchangeably to calculate genotype probabilities. • Sequence-based alleles were characterized in a Norwegian population. • aSTRs and iSNPs alleles were obtained from 371 samples. • The discriminatory advantage of using sequence-based over length-based alleles was confirmed. • Southern and Northern Norway, and Denmark aSTR allele frequencies were similar. • MAF values of iSNPs were comparable to frequencies in a larger dataset. [ABSTRACT FROM AUTHOR]

The former Kingdom of Granada, comprising the provinces of Granada, Málaga, and Almería (GMA), was once inhabited for over 700 years (711–1492 AD) by a North African population, which influenced its creation and establishment. The genetic data on 15 autosomal short tandem repeats (STRs) in 245 unrelated donor residents were examined in order to assess any possible admixture. As the two surnames in Spain follow an inheritance similar to the Y chromosome, both surnames of all 245 unrelated individuals were queried and annotated. The Spanish Statistics Office website was consulted to determine the regions with the highest frequency of individuals born bearing each surname. Further, several heraldry and lineage pages were examined to determine the historical origin of the surnames. By AMOVA and STRUCTURE analysis, the populations of the three provinces can be treated genetically as a single population. The analysis of allele frequencies and genetic distance demonstrated that the GMA population lay in the Spanish population group but was slightly more similar to the North African populations than the remainder of the Spanish populations. In addition, the surnames of most individuals originated in Northern and Central Spain, whereas most surnames had higher frequencies in Southern Spain. These results confirm that the GMA population shows no characteristics that reflect a greater genetic influence of North African people than the rest of the populations of the Iberian Peninsula. This feature is consistent with the historical data that African inhabitants were expelled or isolated during the repopulation of the region with Spaniards from Northern Spain. The knowledge of present populations and their genetic history is essential for better statistical results in kinship analyses.

The present study was designed to explore the STR diversity and genomic history of the inhabitants of the most populous subdivision of the country. A set of 24 hypervariable autosomal STRs was used to estimate the genetic diversity within the studied population. A panel of 15 autosomal STRs, which is most common in the previously reported data sets, was used to estimate the genetic diversity between the studied population, and obtained unique relations were reported here. The genetic diversity and polymorphism among 636 individuals of different ethnic groups, residing in Bareilly, Pilibhit, Shahjahanpur, Gorakhpur, Jhansi, and Varanasi regions of Uttar Pradesh, India, was investigated. This investigation was carried out via 24 autosomal STRs. The 24 loci studied showed the highest value of combined power of discrimination (CPD = 1), combined power of exclusion (CPE = 0.99999999985), combined paternity index (CPI = 6.10 × 109) and lowest combined matching probability (CPM = 7.90 × 10−31). The studied population showed genetic closeness with the population of Uttarakhand, the Jats of Delhi,the Jat Sikh (Punjab), and the population of Rajasthan. Among the tested loci, SE33 and Penta E were found to be most useful in terms of the highest discrimination power, lowest matching probability, the highest power of exclusion, and highest polymorphism information content for the Uttar Pradesh population. [ABSTRACT FROM AUTHOR]

In this study, Japanese and Han Chinese individuals (n = 32, each) were genotyped for 261 autosomal STRs, and allele frequencies were calculated for each locus in each population. The average number of alleles for all loci in Japanese and Han Chinese populations was 6.65 and 6.56, respectively. The tests for deviations from HWE performed using an exact test showed that the number of STRs (P > 0.05) in Japanese and Han Chinese populations was 236 and 241, respectively. Calculation of forensic parameters showed heterozygosity, and the exclusion means in the Japanese population were 0.7185 and 4813 and those in the Han Chinese population were 0.7308 and 0.5008. In addition, population genetic analyses, such as principal component analysis and factorial correspondence analysis, were performed and a differential formula with likelihood ratios was applied for various number of STR loci based on the effectiveness of differentiation between the two populations. Accordingly, this study suggests that statistical differentiation between genetically close populations, such as the Japanese and Han Chinese populations, is possible if approximately 40–50 effective STR loci are analyzed. [ABSTRACT FROM AUTHOR]

The Xinjiang Uyghur Autonomous Region of China (XUARC) harbors almost 50 ethnic groups including the Uyghur (UGR: 45.84%), Han (HAN: 40.48%), Kazakh (KZK: 6.50%), Hui (HUI: 4.51%), Kyrgyz (KGZ: 0.86%), Mongol (MGL: 0.81%), Manchu (MCH: 0.11%), and Uzbek (UZK: 0.066%), which make it one of the most colorful regions with abundant cultural and genetic diversities. In our previous study, we established allelic frequency databases for 14 autosomal short tandem repeats (STRs) for four minority populations from XUARC (MCH, KGZ, MGL, and UZK) using the AmpFlSTR® Identifiler PCR Amplification Kit. In this study, we genotyped 2,121 samples using the GoldenEye™ 20A Kit (Beijing PeopleSpot Inc., Beijing, China) amplifying 19 autosomal STR loci for four major ethnic groups (UGR, HAN, KZK, and HUI). These groups make up 97.33% of the total XUARC population. The total number of alleles for all the 19 STRs in these populations ranged from 232 (HAN) to 224 (KZK). We did not observe any departures from the Hardy–Weinberg equilibrium (HWE) in these populations after sequential Bonferroni correction. We did find minimal departure from linkage equilibrium (LE) for a small number of pairwise combinations of loci. The match probabilities for the different populations ranged from 1 in 1.66 × 1023 (HAN) to 6.05 × 1024 (HUI), the combined power of exclusion ranged from 0.999 999 988 (HUI) to 0.999 999 993 (UGR), and the combined power of discrimination ranged from 0.999 999 999 999 999 999 999 983 (HAN) to 0.999 999 999 999 999 999 999 997 (UGR). Genetic distances, principal component analysis (PCA), STRUCTURE analysis, and the phylogenetic tree showed that genetic affinity among studied populations is consistent with linguistic, ethnic, and geographical classifications. [ABSTRACT FROM AUTHOR]

Due to its strategic location, Tunisia witnessed the succession and influence of many civilisations throughout history. However, the majority of studies carried out on Tunisia are focussed on Barbarian ethnicity. To estimate genetic diversity and genetic structure of three Tunisian populations using autosomal STRs. 278 individuals were analysed for sixteen STRs. Allele frequencies and statistical parameters were determined. The studied populations showed genetic affinity with geographically close populations. AMOVA showed no genetic difference between the Tunisian populations. Nevertheless, the variance between the populations of the same group was significant, reflecting their heterogeneity even though they came from the same geographical area, and had the same ethnicity and complex demographic history. Our results strongly supported the application of autosomal genetic markers in anthropological and forensic studies. The analyses conducted at the 15-loci level provide the resolution to assess the phylogenetic relationships among the populations examined and other geographically targeted worldwide populations, while the results resulting from the 10-loci studies provide an understanding of the relationships and origins of the North African populations. Furthermore, the current report demonstrates that the battery of autosomal STRs reported are useful, providing the power of discrimination for forensic and paternity analyses. [ABSTRACT FROM AUTHOR]

Short tandem repeats (STRs) play an essential role in forensic genetics due to their high degree of polymorphisms, wide distributions and easy detection method. In this study, allelic frequencies and forensic statistical parameters of the 19 autosomal STR loci in a Kazak ethnic group were calculated, and its genetic relationships with reference populations were assessed in order to understand population structure better and enrich population genetic data for forensic practice in Chinese Kazak ethnic group. There were 226 identified alleles with the corresponding allelic frequencies ranging from 0.0008 to 0.5295 in the 628 unrelated healthy Kazak individuals in Xinjiang Uygur Autonomous Region. All autosomal STRs were conformed to the Hardy-Weinberg equilibrium after Bonferroni’s correction. The cumulative power of discrimination and the combined probability of exclusion of all the 19 autosomal STRs were 0.999 999 999 999 999 999 999 997 162 and 0.999 999 994 484, respectively. Furthermore, the DA distances and Fixation index values of pairwise populations, principal component analysis, multidimensional scaling analysis, phylogenetic tree analysis and structure analysis were conducted to probe the genetic relationships between the Kazak group and other reference populations. The population genetic results showed that these 19 autosomal STR loci were characterised by high genetic diversities in the Kazak group. Furthermore, the studied Kazak group had close genetic relationships with the Uyghur group and the Uzbek group. The present results may facilitate understanding the genetic background of the Chinese Xinjiang Kazak group.

The Xinjiang Uyghur Autonomous Region of China (XUARC) harbors almost 50 ethnic groups including the Uyghur (UGR: 45.84%), Han (HAN: 40.48%), Kazakh (KZK: 6.50%), Hui (HUI: 4.51%), Kyrgyz (KGZ: 0.86%), Mongol (MGL: 0.81%), Manchu (MCH: 0.11%), and Uzbek (UZK: 0.066%), which make it one of the most colorful regions with abundant cultural and genetic diversities. In our previous study, we established allelic frequency databases for 14 autosomal short tandem repeats (STRs) for four minority populations from XUARC (MCH, KGZ, MGL, and UZK) using the AmpFlSTR® Identifiler PCR Amplification Kit. In this study, we genotyped 2,121 samples using the GoldenEye™ 20A Kit (Beijing PeopleSpot Inc., Beijing, China) amplifying 19 autosomal STR loci for four major ethnic groups (UGR, HAN, KZK, and HUI). These groups make up 97.33% of the total XUARC population. The total number of alleles for all the 19 STRs in these populations ranged from 232 (HAN) to 224 (KZK). We did not observe any departures from the Hardy–Weinberg equilibrium (HWE) in these populations after sequential Bonferroni correction. We did find minimal departure from linkage equilibrium (LE) for a small number of pairwise combinations of loci. The match probabilities for the different populations ranged from 1 in 1.66 × 1023 (HAN) to 6.05 × 1024 (HUI), the combined power of exclusion ranged from 0.999 999 988 (HUI) to 0.999 999 993 (UGR), and the combined power of discrimination ranged from 0.999 999 999 999 999 999 999 983 (HAN) to 0.999 999 999 999 999 999 999 997 (UGR). Genetic distances, principal component analysis (PCA), STRUCTURE analysis, and the phylogenetic tree showed that genetic affinity among studied populations is consistent with linguistic, ethnic, and geographical classifications.

Genetic variability of Roma population was shaped by the strong influence of genetic drift and gene flow during the migrations from their ancestral homeland in Indian subcontinent towards Europe. In addition, social stigmatization in many European countries, as a consequence of different cultural heritage and social practices, induced further genetic differentiation and sub structuring within the population. Although many populations genetic studies on European Roma were carried out, the genetic structure of the Serbian Roma has not been described yet, since only the modest number of individuals from this territory was analyzed. The main aim of this study was the characterization of genetic variability of the Roma and the assessment of intrapopulation genetic differentiation based on the analysis of 21 autosomal STR loci of 259 self-identified unrelated individuals from Serbia. Intrapopulation analysis revealed divergence of Roma groups illustrating the effect of the historical events after their arrival on Balkan Peninsula and emphasizing significance of the religious affiliation on admixture with autochthonous population. Genetic distance analysis showed the greatest similarity of the studied population with the Middle Eastern populations, while South Asian and European population were more distant. Our results demonstrate that Roma groups in this region of Balkan Peninsula do not represent completely isolated, but rather admixed populations with different proportion of gene flow with other Roma and non-Roma groups.

This document is a retraction and correction notice for an article titled "The heart of silk road 'Xinjiang', its genetic portray, and forensic parameters inferred from autosomal STRs." The correction involves the removal of Supplementary Table S1 due to concerns over potentially identifiable data being disclosed without appropriate consent. The authors apologize for the error and state that it does not change the scientific conclusions of the article. The document also includes contact information for the authors and information about the publication and copyright. [Extracted from the article]

The use of 21 autosomal STR loci for human identification has been gaining popularity throughout the world. It has been indicated that the forensic statistical parameters for supporting the use of 21 STR loci varied among different populations. Hitherto, such data for the diverse Malaysian populations remain unreported, rendering doubts in the court of law about its real ability for human identification in Malaysian population. Using the GlobalFiler™ Express PCR Amplification Kit, complete DNA profiles of 21 STR loci from buccal swabs of convicted Malaysian criminal (n = 570; 190 each for Malays, Chinese, and Indians) (by the year 2016–2017) were analyzed for their allele frequencies, exact test of Hardy-Weinberg equilibrium, observed and expected heterozygosity, power of discrimination, power of exclusion, match probability, and polymorphism information content. Most of the loci were found to be in the Hardy-Weinberg equilibrium after the Bonferroni correction. Being the most informative locus, SE33 demonstrated the highest power of discrimination and power of exclusion, indicating its usefulness to discriminate individuals. In contrast, TPOX had the lowest power of discrimination and power of exclusion, as well as being the less informative genetic locus for all Malaysian population studied here. The probabilities that two individuals would share the same DNA profiles among the Malaysian Malays, Chinese, and Indians, as well as in general Malaysian population, were 1.3713 × 10−25, 2.8822 × 10−25, 7.5668 × 10−26, and 1.0385 × 10−26, respectively. The results obtained here were found comparable with similar studies reported in other populations. Hence, its robustness for forensic human identification among the Malaysian populations is, therefore, statistically supported. [ABSTRACT FROM AUTHOR]

Genetic structure of a population can be influenced by evolutionary processes and cultural histories which can alter the frequencies of different variants at particular genetic markers. These characteristics make DNA evidence suitable for forensic applications. Little relevant data are available from the interior Sindhi population; thus, in the current study, we have investigated 15 autosomal STRs in 181 unrelated individuals belonging to the interior parts of Sindh Pakistan, to establish its lineage and parameters of forensic interest. These STRs revealed a high power of discrimination (CPD), power of exclusion (CPE) and matching probability (CMP) are 0.9999999999999999968997, 0.99998612 and 3.1003 × 10–18 respectively. The genetic distances, neighbour‐joining (NJ) tree, interactivity test and principal component analysis (PCA) based on 15 autosomal STR loci showed that the interior Sindhi population had a closer genetic relationship with Pakistani populations and distant relationships with regional (India and Afghanistan) populations. The present findings exhibited that STRs included in AmpFLSTR Identifiler kit (Applied Biosystems) are genetically polymorphic in the interior Sindhi population of Pakistan. This study provides valuable population genetic data for the genetic information study, forensic human individual identification and paternity testing. [ABSTRACT FROM AUTHOR]

Background: Recent genomic analyses suggest that the current North African gene pool was mainly influenced by population flow coming from the East that altered the genetic structure of autochthonous Berber populations. Such genetic flow has not been extensively addressed yet using North African populations of Middle-eastern origin as reference. Aim: To discern the Middle-eastern component in the genetic background of Tunisian Arabs and evaluate the extent of gene flow from the Middle East into North African autochthonous Berber populations. Subjects and methods: This study has examined 113 Tunisians of well-known Arabian origin from Kairouan region, using 15 autosomal Short Tandem Repeats (STRs) loci. Results: No deviations from Hardy-Weinberg equilibrium were observed and all loci presented high levels of heterozygosity. Principal coordinate and STRUCTURE analyses were consistent in clustering together North African and Middle Eastern populations, likely reflecting the recent gene flow from the East dating back to the Arab conquest period. This demographic migration and the Arabisation process that submerged the original Berber language and customs seems to have be accompanied by substantial gene flow and genetic admixture. Conclusion: This study represents an additional step to obtain a comprehensive understanding of the complex demographic history of North African populations.

Objectives: Investigation of genetic diversity of the 21 autosomal STR loci included in the GlobalFilerTM PCR Amplification Kit in 529 Pakistani individuals belonging to the Punjabi, Pashtun, Sindhi, Saraiki, and Baloch ethnic groups. Population genetic parameters and forensic informative metrics for each group were evaluated. Results: SE33 showed the greatest power of discrimination in all populations studied. The combined match probability ranged from 8.06E−27 (Saraiki) to 1.05E−26 (Baloch), and the combined power of exclusion ranged from 0.99999999902 (Punjabi) to 0.99999999964 (Pashtun). D12S391 in the Baloch population and D2S441 in the Saraiki population showed deviation from Hardy-Weinberg equilibrium. Conclusion: Significant genetic distances were observed between the Punjabi, Pashtun, and Baloch populations. This study supports the utilization of the GlobalFilerTM STR kit for forensic applications in Pakistan. [ABSTRACT FROM AUTHOR]

Highlights • GlobalFiler (21-STR) genotypes reported for 523 Saudi Arabian males. • Significant differences in allele frequencies among five geographical sub-regions. • Heterozygote deficiency observed at nearly all loci in all regions, likely reflecting history of consanguineous marriage. • Autosomal sub-regional pattern contrasts with previously described pattern of Y-STR variation in the same samples. • Population structure and heterozygote deficiency should be accounted for in forensic interpretation of Saudi STR profiles. Abstract Variation in the 21 autosomal STRs detected by the GlobalFiler multiplex was investigated in a sample of 523 indigenous male Arabs from five geographic regions of Saudi Arabia. Although allele frequencies for the entire dataset were found to be broadly similar to those determined in previous studies of Saudi citizens, significant differences were found among regions. Heterozygote deficiency was observed at nearly all loci in all regions, probably as a consequence of high levels of consanguineous marriage; in the case of D2S1338, which showed the largest deviation from Hardy-Weinberg equilibrium, the presence of a null allele also played a part. Genetic distances were greatest between the Northern and Southern regions, whilst the West, Central and East appeared most similar to each other, and to previously published surveys. This contrasts with previously described variation among paternal lineages in the same sample-set: Y-chromosome variation was limited within the North/Central/South core compared with the more diverse East and West. Differences between autosomal and Y-chromosomal patterns may reflect genetic drift on the Y chromosome, exacerbated by prevalent patrilineal descent groups in different regions. [ABSTRACT FROM AUTHOR]

We performed forensic investigations on a handkerchief containing seminal fluid deposited 100 years earlier. The aim was to verify the possibility to achieve a complete genetic profile exceeding the limit of success reached until today with a partial semen stain profile stored up to 50 years. The current forensic methods were carried out: Alternative Light Source (ALS), Prostate-Specific Antigen (PSA) Test, autosomal and Y-chromosome Short Tandem Repeats (STRs). ALS inspection was a crucial method in the success of the analysis. On a dried semen stain, fluorescence remains constant for a very long time, allowing possibility to minimize the fabric sample to analyze, in order to preserve specimen for future defense guarantees or to protect historical finding. We achieved positive results in 3 of 6 traces, PSA and DNA results were concordant, only those cuttings that tested positive for PSA yielded DNA profiles. A complete male profile was generated by AmpFlSTR Identifiler Plus and 16 loci profile by AmpFLSTR Yfiler. Considering some historical sources that attributed this handkerchief dated 1916, to a famous Italian poet, the DNA profile found on the handkerchief was compared with a living male descendant, and the comparison of the Y-STR between the two gave positive results, confirming the reliability of the outcomes. The findings achieved by the current forensic method empower the application of this methodology to other forensic cases, especially in past unresolved cases. [ABSTRACT FROM AUTHOR]

We conducted a study of 182 unrelated adult individuals belonging to Bhuiyan population resident of Eastern India in order to estimate genetic polymorphism by using 20 autosomal STR loci. The results obtained from this study were compared with the published data of Indian and neighbouring countries' populations. This research study is expected to contribute significantly to forensic investigations for human identification and parentage testing. [ABSTRACT FROM AUTHOR]

Short tandem repeats (STRs) incur in length mutations that involve the loss or gain of repeats. STR mutation rates are usually estimated considering the rates of observed Mendelian incompatibilities in one generation familial configurations. When considering multistep mutations, for the autosomal and X-chromosomal modes of genetic transmission, underestimations are inevitable when using this approach (MIA), due to the occurrence of mutational events deceptively perceived as involving fewer steps. The rate of this occurrence depends on the mode of genetic transmission considered, the parental origin of the mutation, the type of familial configuration considered, and the genotypic background of the progenitor(s). MIA biases were weighted and compared for the diploid and haplodiploid modes of transmission, using familial genotypic configurations (parent(s)-child duos and trios) generated resorting to Python™ and real population databases from Norway, Somalia, and Spain for 10 Aut-STRs and Argentina, Eastern Asia, and Northern Europe for 12 X-STRs. One two- or one three-step mutation was simulated in each of the 1,000,000 familial configurations. The frequency with which mutations could be interpreted as involving fewer steps, when the most parsimonious reasoning is employed, was computed. Results showed that the magnitude and type of biases depend on the type of familial data and the genetic mode of transmission considered, being higher in duos than in trios, both in autosomes and the X chromosome. Indeed, whether X- or Aut-STRs are analyzed, trios generally provide better estimates and should be favored over duos. The pooling of the two types of data is not advised. The greater the number of steps involved in the mutation, the worst the estimates obtained. In X-chromosomal analyzes, trios with a paternal mutation presented the best estimates and mother-daughter duos the worst; mother-son duos showed similar estimates to trios when a maternal mutation was considered. [ABSTRACT FROM AUTHOR]

To explore the genetic diversity and establish the allelic database of the population of Rajasthan, we assessed 571 randomly selected unrelated healthy individuals residing in the state. Blood samples of the selected individuals were collected with the compliance of ethical standards. Locus Penta E was observed to be the most polymorphic (0.908), whereas locus TPOX was observed to be the least polymorphic (0.639). The observed heterozygosity ranged from a minimum of 0.667 (TPOX) to a maximum of 0.925 (Penta E). The combined value of the power of discrimination (PD) and power of exclusion (PE) for all the studied 20 short tandem repeat (STR) loci were observed to be 1 and 0.999999997560235 respectively. The combined values of matching probability (PM) and paternity index (PI) for all the studied 20 STR loci were 7 × 10−26 and 4 × 108 respectively. The obtained genetic data are useful for forensic DNA applications and expected to enrich the genetic database of Indian populations. [ABSTRACT FROM AUTHOR]

The capability to achieve biogeographic ancestry (BGA) information from DNA profiles have been largely explored in forensic genetics because of its potential usefulness in providing investigative clues. For law enforcement and security purposes, when genetic data have been obtained from unknown evidence, but no reference samples are available and no hints come out from DNA databases, it would be extremely useful at least to infer the ethno-geographic origin of the stain donor by just examining traditional STRs DNA profiles. Current protocols for ethnic origin estimation using STRs profiles are usually based on Principal Component Analysis approaches and Bayesian methods. The present study provides an alternative approach that involves the use of target multivariate data analysis strategies for estimation of the BGA information from unknown biological traces. A powerful multivariate technique such as Partial Least Squares-Discriminant Analysis (PLS-DA) has been applied on NIST U.S. population datasets containing, for instance, the allele frequencies of African-American, Asian, Caucasian and Hispanic individuals. PLS-DA approach provided robust classifications, yielding high sensitivity and specificity models capable of discriminating the populations on ethnic basis. Finally, a real casework has been examined by extending the developed model to smaller and more geographically-restricted populations involving, for instance, Albanian, Italian and Montenegrian individuals. [ABSTRACT FROM AUTHOR]

Autosomal short tandem repeats (STRs) have been widely used in forensic investigations. Prior to the application of any DNA based identification method, it is essential to estimate the allele frequencies and forensic statistical parameters of targeted STR loci in each population in order to provide a more precise reference database for forensic investigation. The GlobalFiler™ Kit is a multiplex assay that combines the 13 original CODIS loci with 7 non-overlapping loci from the expanded European Standard Set (ESS), as well as the highly discriminating SE33 locus, two Y-based loci and the sex determining maker, Amelogenin. The full complement of loci in the GlobalFiler™ Kit are: D13S317, D7S820, D5S818, CSF1PO, D1S1656, D12S391, D2S441, D10S1248, D18S51, FGA, D21S11, D8S1179, vWA, D16S539, TH01, D3S1358, AMEL, D2S1338, D19S433, DYS391, TPOX, D22S1045, SE33 and a Y-specific insertion/deletion locus (Yindel). The 6-dye GlobalFiler™ PCR Amplification kit (ThermoFisher Scientific) comprises 21 autosomal STRs have already been proven to be able to provide reliable DNA profiling results and enhance the power of discrimination between individuals. In this study, we are presenting an analysis of GlobalFiler STR loci on 209 unrelated individuals from Serbia. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The main aim of this work was to contribute to the knowledge of pre‐Hispanic genetic variation and population structure among the South‐central Andes Area by studying individuals from Quebrada de Humahuaca, North‐western (NW) Argentina. Materials and methods: We analyzed 15 autosomal STRs in 19 individuals from several archaeological sites in Quebrada de Humahuaca, belonging to the Regional Developments Period (900–1430 AD). Compiling autosomal, mitochondrial, and Y‐chromosome data, we evaluated population structure and differentiation among eight South‐central Andean groups from the current territories of NW Argentina and Peru. Results: Autosomal data revealed a structuring of the analyzed populations into two clusters which seemed to represent different temporalities in the Andean pre‐Hispanic history: pre‐Inca and Inca. All pre‐Inca samples fell into the same cluster despite being from the two different territories of NW Argentina and Peru. Also, they were systematically differentiated from the Peruvian Inca group. These results were mostly confirmed by mitochondrial and Y‐chromosome analyses. We mainly found a clearly different haplotype composition between clusters. Discussion: Population structure in South America has been mostly studied on current native groups, mainly showing a west‐to‐east differentiation between the Andean and lowland regions. Here we demonstrated that genetic population differentiation preceded the European contact and might have been more complex than thought, being found within the South‐central Andes Area. Moreover, divergence among temporally different populations might be reflecting socio‐political changes occurred in the evermore complex pre‐Hispanic Andean societies. [ABSTRACT FROM AUTHOR]

In preparation for the growing use of massively parallel sequencing (MPS) technology to genotype forensic STRs, a comprehensive genomic audit of 73 STRs was made in 2016 [Parson et al., Forensic Sci. Int. Genet. 22, 54–63]. The loci examined included miniSTRs that were not in widespread use, but had been incorporated into MPS kits or were under consideration for this purpose. The current study expands the genomic analysis of autosomal STRs that are not commonly used, to include the full set of developed miniSTRs and an additional 24 STRs, most of which have been recently included in several supplementary forensic multiplex kits for capillary electrophoresis. The genomic audit of these 47 newly-adopted STRs examined the linkage status of new loci on the same chromosome as established forensic STRs; analyzed world-wide population variation of the newly-adopted STRs using published data; assessed their forensic informativeness; and compiled the sequence characteristics, repeat structures and flanking regions of each STR. A further 44 autosomal STRs developed for forensic analyses but not incorporated into commercial kits, are also briefly described. [ABSTRACT FROM AUTHOR]

Background: Recent genomic analyses suggest that the current North African gene pool was mainly influenced by population flow coming from the East that altered the genetic structure of autochthonous Berber populations. Such genetic flow has not been extensively addressed yet using North African populations of Middle-eastern origin as reference. Aim: To discern the Middle-eastern component in the genetic background of Tunisian Arabs and evaluate the extent of gene flow from the Middle East into North African autochthonous Berber populations. Subjects and methods: This study has examined 113 Tunisians of well-known Arabian origin from Kairouan region, using 15 autosomal Short Tandem Repeats (STRs) loci. Results: No deviations from Hardy-Weinberg equilibrium were observed and all loci presented high levels of heterozygosity. Principal coordinate and STRUCTURE analyses were consistent in clustering together North African and Middle Eastern populations, likely reflecting the recent gene flow from the East dating back to the Arab conquest period. This demographic migration and the Arabisation process that submerged the original Berber language and customs seems to have be accompanied by substantial gene flow and genetic admixture. Conclusion: This study represents an additional step to obtain a comprehensive understanding of the complex demographic history of North African populations. [ABSTRACT FROM AUTHOR]

Since prehistoric times, Mon-Khmer speaking people have been recognized as indigenous ethnic groups living in northern Thailand. After the period of Tai colonization in the thirteenth century CE, the Mon-Khmer inhabitants were fragmented; some were expelled to rural areas while some were integrated into the mainstream of Tai society. Autosomal STR variations revealed that the present-day Mon-Khmer people could be genetically divided into two clusters. This finding appears to be consistent with the level of historical contact with the Tai majority ethnic groups. The cluster consisting of the Khamu, Lua, Paluang and Htin people, indicate that they have lived in remote areas and have had little historical contact with the Tai people. In this way, they appeared to have maintained aspects of their Mon-Khmer ancestral genetic bloodline but have genetically diverged from the Tai people. The cluster comprised of the Mon and Lawa people had an exclusively close relationship with the Tai people during the establishment of the prosperous Lan Na Kingdom. A fraction of the Tai genetic component investigated among the Mon people and some Lawa populations reflected the evidence of genetic admixture. However, some Lawa people, who have lived in the mountainous area of Mae Hong Son Province have exhibited a unique gene pool, which might have been shaped by the founder effect that occurred during their historical fragmentation. The rise of the genetic assimilation of the hill-tribe Karen people into the Mon-Khmer and the Tai gene pools indicated that different languages, cultures, and geographical distances have lost their power as barriers of inter-ethnic marriages in the present day. [ABSTRACT FROM AUTHOR]

The interpretation of complex DNA profiles may differ between laboratories and reporting officers, which can lead to discrepancies in the final reports. In this study, we assessed the intra and inter laboratory variation in DNA mixture interpretation for three European ISO17025-accredited laboratories. To this aim, 26 reporting officers analyzed five sets of DNA profiles. Three main aspects were considered: 1) whether the mixed DNA profiles met the criteria for comparison to a reference profile, 2) the actual result of the comparison between references and DNA profiling data and 3) whether the weight of the DNA evidence could be assessed. Similarity in answers depended mostly on the complexity of the tasks. This study showed less variation within laboratories than between laboratories which could be the result of differences between internal laboratory guidelines and methods and tools available. Results show the profile types for which the three laboratories report differently, which informs indirectly on the complexity threshold the laboratories employ. Largest differences between laboratories were caused by the methods available to assess the weight of the DNA evidence. This exercise aids in training forensic scientists, refining laboratory guidelines and explaining differences between laboratories in court. Undertaking more collaborative exercises in future may stimulate dialog and consensus regarding interpretation. For training purposes, DNA profiles of the mixed stains and questioned references are made available. [ABSTRACT FROM AUTHOR]

The present study aimed to establish human earwax as a potential source of DNA evidence that could be effectively used in human identification. Sixty earwax samples were obtained from 15 healthy male and female Saudi volunteers living in Riyadh, Saudi Arabia. Four consecutive earwax swab samples were obtained from each volunteer and stored for 1, 15, 30 and 60 days. Earwax samples were stored at room temperature (20-22 °C). Reference oral swab was also taken from each volunteer. DNA was extracted by QIAamp DNA Mini kit and quantified by real-time polymerase chain reaction (RT-PCR) on 7500 Thermal Cycler. Autosomal STR loci were amplified using AmpFLSTR™ Identifiler™ Plus PCR Amplification Kit (Thermo Fisher Scientific, Carlsbad, CA, USA). Amplified fragments were size separated and analyzed on a 3500 Genetic Analyzer. Complete autosomal STR profiles were obtained from the earwax swabs of all the volunteers stored up to 30 days after the collection. Some STR profiles were partially obtained 60 days after the earwax collection. Allelic drop-out, allelic drop-in, and stutters were seen in earwax samples analyzed 60 days after the collection. The results have shown that human earwax can be a potential source of DNA evidence for human identification up to 30 days after the earwax collection. It is recommended to quickly analyze earwax samples or store them at room temperature or at -10 °C after their recovery from the crime scene.

Since 1992, the Spanish and Portuguese-Speaking Working Group of the ISFG (GHEP-ISFG) has been organizing annual Intercomparison Exercises (IEs) coordinated by the Quality Service at the National Institute of Toxicology and Forensic Sciences (INTCF) from Madrid, aiming to provide proficiency tests for forensic DNA laboratories. Each annual exercise comprises a Basic (recently accredited under ISO/IEC 17043: 2010) and an Advanced Level, both including a kinship and a forensic module. Here, we show the results for both autosomal and sex-chromosomal STRs, and for mitochondrial DNA (mtDNA) in two samples included in the forensic modules, namely a mixture 2:1 (v/v) saliva/blood (M4) and a mixture 4:1 (v/v) saliva/semen (M8) out of the five items provided in the 2014 GHEP-ISFG IE. Discrepancies, other than typos or nomenclature errors (over the total allele calls), represented 6.5% (M4) and 4.7% (M8) for autosomal STRs, 15.4% (M4) and 7.8% (M8) for X-STRs, and 1.2% (M4) and 0.0% (M8) for Y-STRs. Drop-out and drop-in alleles were the main cause of errors, with laboratories using different criteria regarding inclusion of minor peaks and stutter bands. Commonly used commercial kits yielded different results for a micro-variant detected at locus D12S391. In addition, the analysis of electropherograms revealed that the proportions of the contributors detected in the mixtures varied among the participants. In regards to mtDNA analysis, besides important discrepancies in reporting heteroplasmies, there was no agreement for the results of sample M4. Thus, while some laboratories documented a single control region haplotype, a few reported unexpected profiles (suggesting contamination problems). For M8, most laboratories detected only the haplotype corresponding to the saliva. Although the GHEP-ISFG has already a large experience in IEs, the present multi-centric study revealed challenges that still exist related to DNA mixtures interpretation. Overall, the results emphasize the need for further research and training actions in order to improve the analysis of mixtures among the forensic practitioners. [ABSTRACT FROM AUTHOR]

Massively parallel sequencing (MPS) technology is gaining interest in the forensic community. The capabilities of high throughput and simultaneously analyses of many markers enable MPS as an attractive method for human forensics. Recent studies have demonstrated the successful application of the MPS system to short tandem repeat (STR) typing. However, not only DNA sequence variations in the repeat regions of STR but also in flanking regions are required to facilitate profiles sharing with capillary electrophoresis (CE)-based typing method. In this study, we constructed a multiplex PCR system for the MPS analysis of 10 autosomal STR loci (D13S317, D16S539, D19S433, D2S441, D3S1358, D5S818, D6S1043, D7S820, TH01, TPOX) by designing amplicons in the size range of 168–273 base pairs. Sequencing results from 165 Chinese unrelated individuals demonstrated 11 variations in the flanking regions between amplification primer binding sites and core repeat motifs. In addition, three loci, D13S317, D5S818, and D7S820, displayed variants adjacent to the core repeats and caused discordances between sequence-based and length-based typing results. Four loci (D3S1358, D2S441, D19S433 and D7S820) demonstrated an increased allele number using MPS-based typing. This study demonstrated that STR typing by MPS could provide more genetic information from both repeat and flanking regions of STR loci, thus improving the diversity and discrimination power of the system in forensic detection. [ABSTRACT FROM AUTHOR]