Chromosome Short Tandem Repeat Research Articles

Application of CPI cutoff value based on parentage testing of duos and trios typed by four autosomal kits.

In this study, we analyzed the application of four autosomal kits and the sensitivity of the combined paternity index (CPI) cutoff value (CPI≥10000) in parentage testing. First, 1442 real trios and 803 real duos were tested using the Goldeneye 25A kit. The Goldeneye 25A kit covers the autosomal short tandem repeat (STR) loci of the other three kits, so we calculated the CPI value of every case for the four kits. Second, three complex close relative kinship cases were also analyzed to evaluate the application of the CPI cutoff value. The CPI values of all trio cases were higher than 10000 using the four kits; the CPI values of all duo cases were higher than 10000 using the Goldeneye 25A kit; and the CPI values of a portion of the duo cases were lower than 10000 using the other three kits. In the three complex close relative cases, the alleged father or mother was not excluded using 40 autosomal STRs. Adding X chromosome short tandem repeats (X-STR) and samples of biological fathers or mothers, the conclusions were confirmed. The four kits were adequate to draw conclusions in the trio cases; the Goldeneye 25A Kit was adequate to draw conclusions in the duo cases; and the other three kits were not sufficient for a portion of the duo cases. The CPI cutoff value was sensitive for real trio and duo cases. In complex close relative kinship cases, high CPI values may result in false conclusions.

Haplotype diversity of 17 Y-STRs in Sheikh population of Punjab.

Y chromosomal short tandem repeat (Y-STR) haplotype diversity of 180 genetically unrelated male individuals from Sheikh population of Punjab Pakistan was studied by amplifying 17 Y-STR markers through the AmpFISTR®Yfiler™ PCR amplification kit. The analysis of data revealed mean discrimination capacity of 0.6438 and matching probability of 0.3561. Sheikh population was also compared with 11 other populations in order to determine its population relationships which indicated that Punjabi Sheikhs have low genetic resemblance with Indian-Balmiki, UAE [Arab], Yousafzai Pathan from Pakistan, and Pathans from Afghanistan. The data of this study could have valuable application in forensic cases, in population genetics studies, and in strengthening the Y-STR database.

Genetic insight into Nigerian population groups using an X-chromosome decaplex system

African populations have higher genetic diversity representing an interesting continent for population genetic studies. A sample set from Nigeria, a West African country on the Gulf of Guinea, was genetically characterized using 10 X chromosomal short tandem repeat polymorphisms (DXS8378, DXS9898, DXS7133, GATA31E08, GATA172D05, DXS7423, DXS6809, DXS7132, DXS9902 and DXS6789). 218 unrelated male individuals belonging to three of the largest ethnic groups of Nigeria, namely Igbo, Hausa and Yoruba were sampled. No evidence for statistically significant LD (p ≤ 0.0011) between all pairs of markers was detected, which may be due to the low power of an exact test in small sample sizes. When studying the genetic affinity among the three studied ethnic groups, no significant differences were detected (FST ≤ 0.0069; p ≥ 0.045) which supports genetic homogeneity among the Nigerian groups for the studied X-chromosome decaplex markers. Parameters for forensic evaluation were also calculated demonstrating the potential application of these markers in diverse kinship scenarios in Nigeria where X-STR analyses may add value.

Sequence characterization of microvariant alleles at DYS627 and DYS458

Y chromosome short tandem repeats (Y-STRs) have been widely used in genetic applications and forensic casework. Recently, we found two intermediate alleles, the DYS627 allele 24.1 and the DYS458 allele 15.3, from Chinese Han population. The two allelic variants have not been recorded by the YHRD database. We have examined the molecular structure of these allelic variants by Sanger sequencing. The results showed that this intermediate allele at DYS627 was confirmed as 24.1, the sequence of which showed a base “A” insertion in the 13th repeat unit, and the intermediate allele at DYS458 was confirmed as 15.3, the sequence of which showed a base “G” deletion in the 12th repeat unit. This may be important for individual identification and paternal kinship testing. Besides, more allelic variants detected can be enriched in the Y-STR database.

Genetic analysis of 50 Y-STR loci in Dong, Miao, Tujia, and Yao populations from Hunan.

To investigate the genetic polymorphism of Y chromosome short tandem repeat (Y-STR) loci in Dong, Miao, Tujia, and Yao minority populations from Hunan Province, China. Fifty Y-STRs (DYS392, DYS389I/II, DYS447, DYS438, DYS527, DYS645, DYS596, DYS391, DYS456, DYS19, DYS593, DYS448, DYS627, DYS557, DYS437, DYS481, DYS533, DYS390, DYS385, DYF387S1, DYS460, DYS393, Y_GATA_H4, DYS439, DYS635, DYS444, DYS643, DYS549, DYS576, DYS570, DYS458, DYS449, DYS518, DYS531, DYS630, DYS622, DYS552, DYS510, DYS459a/b, DYS446, DYS443, DYS587, Y_GATA_A10, DYS520, DYS522) were analyzed for 2553 unrelated healthy male individuals from Hunan (643 Dong males, 666 Miao males, 633 Tujia males, 611 Yao males) using AGCU Y37 and AGCU Y SUPP STR amplification system. There were 624 different haplotypes in 643 unrelated Dong males, 662 in 666 unrelated Miao males, 627 in 633 unrelated Tujia males, and 587 in 611 unrelated Yao males. The haplotype diversities of Dong, Miao, Tujia, and Yao were determined as 0.999879, 0.999982, 0.999970, and 0.999860, respectively. Analysis of molecular variance (AMOVA) tests demonstrated that genetic distance between Miao and Tujia was the smallest (0.0003), while the genetic distance between Dong and Yao was the largest (0.0252). The 50 Y-STR loci in the four minority populations from Hunan Province revealed a highly polymorphic genetic distribution, which showed a high potential for population genetics and forensic practice.

Population data of 23 Y chromosome STR loci for the five major human subpopulations of Ghana.

In this study, 268 samples for unrelated males belonging to the five major human subpopulation groups in Ghana (Akan, Ewe, Mole-Dagbon, Ga-Dangme and Guang) were genetically characterised for 23 Y chromosome short tandem repeat (STR) loci using the Powerplex® Y23 STR kit. A total of 263 complete haplotypes were recorded of which 258 were unique. The haplotype diversity, discriminating capacity and match probability for the pooled population data were 0.9998, 0.9627 and 0.0039, respectively. The pairwise genetic distance (RST) for the Ghanaian datasets and other reference populations deposited in the Y-STR Haplotype Reference Database (YHRD) were estimated and mapped using multidimensional scaling (MDS) plot. The Guang and Ewe were significantly different from the Akan, Mole-Dagbon and Ga-Dangme. However, the five Ghanaian datasets were all plotted close together with other African populations in the MDS data mapping.

Genetic polymorphisms and mutation rates of 16 X-STRs in a Han Chinese population of Beijing and application examples in second-degree kinship cases.

As a supplementary tool in forensic cases, X chromosomal short tandem repeats (X-STRs) might bridge large pedigree gaps and bring inspiration to forensic practices for the special mode of inheritance. To standardize the application of X-STRs, the DNA Commission of the International Society for Forensic Genetics (ISFG) presented recommendations concentrating on biostatistical evaluations. Following this guideline, in this study, 1247 (655 females and 592 males) unrelated individuals and 770 families originating from a Han Chinese population of Beijing were investigated with 16 X-STRs. The combined PDF and PDM were 0.999999999999994 and 0.999999997, respectively. The combined MECKrüger, MECKishida, MECDesmarais, and MECDesmarais duo were 0.999972736708864, 0.999999975670766, 0.999999975720931, and 0.999993489709197, respectively. In addition, a population comparison demonstrated that genetic heterogeneity widely exists between the Han population of Beijing and other populations, especially southern Han Chinese, European, and West African populations. Additionally, the overall mutation rates of the paternal and maternal germlines of the 16 X-STRs were 0.0021 and 0.0003, respectively. Among them, HPRTB showed the highest paternal mutation rate of 0.0094. Finally, based on these forensic parameters, the likelihood ratios of four second-degree kinship cases were evaluated. Comparing with autosomal STR, X-STR showed significant advantages for hypothesis exclusion. Our study indicated that the 16 X-STR loci are highly polymorphic in the Han population of Beijing and could be a satisfactory complimentary tool for forensic applications.

RETRACTED ARTICLE: Y Chromosomal STR haplotypes in Chinese Uyghur, Kazakh and Hui ethnic groups and genetic features of DYS448 null allele and DYS19 duplicated allele.

Y Chromosomal short-tandem repeats (Y-STRs) provide valuable information that can be used for forensic investigation and population studies. The Yfiler® Plus PCR Amplification Kit allows the multiplex amplification of 27 Y-STRs, including seven rapidly mutating markers. With the kit, 447 unrelated males of three minorities (161 Uyghurs, 130 Kazakhs and 156 Huis) from the Xinjiang Uighur Autonomous Region of China were analysed in this study. The gene diversity values of the 27 Y-STRs in the Uyghur, Kazakh and Hui groups ranged from 0.4770 to 0.9545, 0.3897 to 0.9375 and 0.4621 to 0.9725, respectively. One specific sequence pattern of null alleles at the DYS448 locus was confirmed. The individuals carrying the null alleles at the DYS448 locus belonged to haplogroups C2b and C2b1a1b1, while those carrying duplicated alleles at the DYS19 locus belonged to haplogroups C2b1a2 and G2a. A total of 155, 118 and 146 distinct haplotypes were obtained in these three groups, respectively, with overall haplotype diversities of 0.9998, 0.9993 and 0.9996, respectively. Compared with 17 Y-plex, 27 Y-plex demonstrated an increased power of discrimination, especially for the Kazakh group. Visualisation of pairwise genetic distances between 24 ethnic groups in China using multidimensional scaling (MDS) demonstrates the distribution of various groups, which is largely in keeping with ethno-geographic patterns.

Genetic structure in the paternal lineages of South East Spain revealed by the analysis of 17 Y-STRs

The genetic data of 17 Y chromosome short tandem repeats in 146 unrelated donor residents in the provinces of Granada, Málaga, and Almería (GMA) were analyzed to determine the genetic legacy of the male inhabitants of the former Kingdom of Granada. A total of 139 unique haplotypes were identified. Observed allele frequencies and haplogroup frequencies were also analyzed. By AMOVA and STRUCTURE analysis, the populations of the 3 provinces could be treated genetically as a single population. The most frequent haplogroup was R1b1b2 (58.22%). By network analysis of all individuals, we observed a distribution according to haplogroup assignment. To improve the characterization of GMA population, it was compared with those of North Africa, the Iberian Peninsula, and southern Europe. In our analysis of allele frequencies and genetic distances, the GMA population lay within the Spanish population group. Further, in the STRUCTURE analysis, there was no African component in the GMA population, confirming that, based on our genetic markers, the GMA population does not reflect any male genetic influence of the North African people. The presence of African haplogroups in the GMA population is irrelevant when their frequency is compared with those in other European populations.

Alleles dropout patterns of Y-short tandem repeats in infertile males with Y chromosome microdeletions

Y chromosomal short tandem repeat (Y-STR) typing is the most commonly used genetic technique in forensic studies. However, there may be a limit to the application of Y-STR in forensic science as Y-STR loci are subject to loss or variation caused by the higher chromosomal structures' spontaneous mutation rate. Located in the long arm of the Y chromosome, azoospermia factor (AZF) have been shown to participate in spermatogenesis and its deletion could cause infertility. However, little is known about the Y-STR dropout pattern in individuals with Y chromosome microdeletions. In this study, 85 infertile males with Y chromosome interstitial deletion were identified and special Y-STR allele dropout patterns were analyzed by employing a Y-STR Commercial Kit and a Y chromosome Deletion Kit. Results demonstrate that AZF a region deletion are related to DYS439-DYS389I-DYS389II alleles dropout, while AZF b region or c region deletions correlate to DYS448 allele dropout. Null DYS385-DYS392-DYS448 alleles were observed in AZF b+c+d region deletion individuals. While null DYS390-Y-GATA-H4-DYS385-DYS392-DYS448 alleles were observed in AZF a+b+c+d large region deletion individuals. Our data suggest that Y chromosome microdeletions may indicate specific Y-STR locus dropout patterns.

Identification of extra alleles in DYS385a/b multi-allelic patterns.

Y chromosome short tandem repeats (Y-STRs) are widely used in forensic DNA analysis. Y-STRs usually genotyped as a monoallelic pattern, or a diallelic pattern at some double-copy loci. Abnormal genotypes with three or four alleles have been reported at DYS385a/b, which is a double-copy locus. However, multi-allelic patterns with more than four alleles have not been reported at this locus. In this study, abnormal five-allelic patterns at DYS385a/b locus were observed in 2 out of 7760 unrelated males from Henan Province, detected by the HG19+14Y fluorescence detection kit; and abnormal six-allelic pattern was observed in 1 out of 4920 unrelated males from Guangdong Province, detected by the AGCU Data Y30 fluorescence kit. The genotypes of these abnormal samples were confirmed again by the Yfiler® Plus and PowerPlex® Y23 kits. In order to understand the genomic structure of the extra alleles at this locus, forward and reverse primers were designed to sequence the three samples. The results showed that the five-banded and six-banded pattern genotype did exist at DYS385a/b locus. These data enriched the knowledge about multi-allelic patterns at DYS385a/b locus, which allowed the use of DYS385a/b profile in forensic analysis, even with multi-allelic patterns.

Mutation analysis of 13 RM Y-STR loci in Han population from Beijing of China.

Two five-color fluorescence multiplex amplification systems of 13 Y chromosome short tandem repeat (Y-STR) loci (DYF387S1, DYF399S1, DYF403S1a/b, DYF404S1, DYS449, DYS518, DYS526a/b, DYS547, DYS570, DYS576, DYS612, DYS626, and DYS627) have been designed. A study was conducted measuring the mutation rates of the 13 Y-STRs in 501 father-son pairs of Han origin in Beijing, China. Among 7515 allele transmissions in 501 father-son pairs, 75 single-step and 2 two-step mutations were observed. Two father-son pairs had mutations at two different loci in 13 Y-STRs. The estimated mutation rates ranged from 2.00 × 10-3 (95% CI 1.00 × 10-4 to 1.11 × 10-2) for the DYF387S1, DYF403S1b, DYS526a, and DYS449 loci to 4.59 × 10-2 (95% CI 2.93 × 10-2 to 6.81 × 10-2) for the DYF399S1 locus. The average mutation rate is 1.02 × 10-2 (95% CI 8.10 × 10-3 to 1.28 × 10-2). Among these Y-STR markers, only DYF399S1, DYS627, DYF403S1a, DYS547, DYS612, and DYS626 had mutation rates higher than 1.00 × 10-2.

Genetic variation for three Y-STR loci: DYS390, DYS518, and DYS643.

Y chromosome short tandem repeats (Y-STRs) are commonly used to analyze male-specific DNA. Although biallelic patterns due to duplication events have been detected at some loci, Y-STRs generally appear as a single peak except for DYS385 because the Y chromosome is haploid. STR loci in regions of segmental duplication by homologous recombination on the Y chromosome exhibit double allelic peaks, rather than single peaks. In this study, we report a bi- and triallelic pattern observed simultaneously in DYS390, DYS518, and DYS643. A bi- and triallelic pattern has not previously been observed simultaneously for these three loci. We also identified the copy number variation in the region including these loci by the microarray-based analysis. Given the peak balance pattern, the copy number variation, and the close position of these three loci on the Y chromosome, we consider that this phenomenon is caused by a segmental duplication in the euchromatin region. By ruling out mixed samples, a common interpretation of multiple peaks, these results have practical implications for the interpretation of Y-STR results in forensics analyses.

Genetic portrait and phylogenetic analysis of an Aksu Uyghur population based on the 19 X-STR system.

The X chromosome has a special mode of inheritance, and is thus a rich resource for population studies. In this study, the allele frequencies and forensic statistics of the 19 X chromosomal short tandem repeat loci were evaluated in 500 Uyghur individuals from Aksu Prefecture in northwest China. We further aimed to study whether the Uyghur populations located in various regions of Xinjiang share similar allele and haplotype frequency distributions, as they have experienced genetic exchanges. Population comparisons, PCA and MDS were performed for the Uyghurs and 27 populations and the results indicate that the Uyghur minority in Aksu has a relatively close phylogenetic relationship with East Asians, especially the Kazakh minority.

Haplotypic polymorphisms and mutation rate estimates of 22 Y-chromosome STRs in the Northern Chinese Han father\u2013son pairs

Y chromosome Short tandem repeats (Y-STRs) analysis has been widely used in forensic identification, kinship testing, and population evolution. An accurate understanding of haplotype and mutation rate will benefit these applications. In this work, we analyzed 1123 male samples from Northern Chinese Han population which including 578 DNA-confirmed father-son pairs at 22 Y-STRs loci. A total of 537 haplotypes were observed and the overall haplotype diversity was calculated as 1.0000 ± 0.0001. Except that only two haplotypes were observed twice, all the rest of the 535 were unique. Furthermore, totally 47 mutations were observed during 13,872 paternal meiosis. The mutation rate for each locus estimates ranged from 0.0 to 15.6 × 10−3 with an average mutation rate 3.4 × 10−3 (95% CI 2.5–4.5 × 10−3). Among the 22 loci, DYS449, DYS389 II and DYS458 are the most prone to mutations. This study adds to the growing data on Y-STR haplotype diversity and mutation rates and could be very useful for population and forensic genetics.

A 21-plex system of STRs integrated with Y-STR DYS391 and ABO typing for forensic DNA analysis

The ABO blood group is considered to be one of the most important markers in forensic testing. Additionally, autosomal short tandem repeat (STR) genotyping continues to be recognized as the dominant technique for determination of human identity, and Y chromosome STR (Y-STR) analysis is becoming increasingly important in solving criminal cases. In this paper, we describe an integrated amplification system of ABO, autosomal STR, and Y-STR genotyping in a single reaction. This system allows for the simultaneous detection of 18 autosomal STR loci (13 Combined DNA Index System [CODIS] loci, as well as D2S1338, D6S1043, D12S391, Penta D, and Penta E), the ABO blood group locus, the Y-STR locus DYS391, and the sex-determining amelogenin locus. Primers were designed and optimized for amplicon sizes from 80–420 bp using a five-dye fluorescent design with the fifth dye reserved for the internal size standard. Sensitivity assays resulted in successful amplification of genomic DNA in the range of 0.250–2.000 ng. A total of 90 individuals from the Chinese Han population were studied using the system and forensic genetic data are presented. We conclude that this integrated system could be an updated and improved solution for forensic DNA analysis.

The association of 22 Y chromosome short tandem repeat loci with initiative–aggressive behavior

Aggressive behavior represents an important public concern and a clinical challenge to behaviorists and psychiatrists. Aggression in humans is known to have an important genetic basis, so to investigate the association of Y chromosome short tandem repeat (Y-STR) loci with initiative–aggressive behavior, we compared allelic and haplotypic distributions of 22 Y-STRs in a group of Chinese males convicted of premeditated extremely violent crimes (n = 271) with a normal control group (n = 492). Allelic distributions of DYS533 and DYS437 loci differed significantly between the two groups (P < 0.05). The case group had higher frequencies of DYS533 allele 14, DYS437 allele 14, and haplotypes 11–14 of DYS533–DYS437 compared with the control group. Additionally, the DYS437 allele 15 frequency was significantly lower in cases than controls. No frequency differences were observed in the other 20 Y-STR loci between these two groups. Our results indicate a genetic role for Y-STR loci in the development of initiative aggression in non-psychiatric subjects.

Mutation rates at 42 Y chromosomal short tandem repeats in Chinese Han population in Eastern China.

Mutation analysis of 42 Y chromosomal short tandem repeats (Y-STRs) loci was performed using a sample of 1160 father-son pairs from the Chinese Han population in Eastern China. The results showed that the average mutation rate across the 42 Y-STR loci was 0.0041 (95% CI 0.0036-0.0047) per locus per generation. The locus-specific mutation rates varied from 0.000 to 0.0190. No mutation was found at DYS388, DYS437, DYS448, DYS531, and GATA_H4. DYS627, DYS570, DYS576, and DYS449 could be classified as rapidly mutating Y-STRs, with mutation rates higher than 1.0 × 10-2. DYS458, DYS630, and DYS518 were moderately mutating Y-STRs, with mutation rates ranging from 8 × 10-3 to 1 × 10-2. Although the characteristics of the Y-STR mutations were consistent with those in previous studies, mutation rate differences between our data and previous published data were found at some rapidly mutating Y-STRs. The single-copy loci located on the short arm of the Y chromosome (Yp) showed relatively higher mutation rates more frequently than the multi-copy loci. These results will not only extend the data for Y-STR mutations but also be important for kinship analysis, paternal lineage identification, and family relationship reconstruction in forensic Y-STR analysis.

Three Reportedly Unrelated Families With Liddle Syndrome Inherited From a Common Ancestor.

Liddle syndrome is considered a rare Mendelian hypertension. We have previously described 3 reportedly unrelated families, native of an Italian area around the Strait of Messina, carrying the same mutation (βP617L) of the epithelial sodium channel. The aims of our study were (1) to evaluate whether a close genomic relationship exists between the 3 families through the analysis of mitochondrial DNA and Y chromosome; and (2) to quantify the genomic relatedness between the patients with Liddle syndrome belonging to the 3 families and assess the hypothesis of a mutation shared through identity by descent. HVRI (the hypervariable region I) of the mitochondrial DNA genome and the Y chromosome short tandem repeats profiles were analyzed in individuals of the 3 families. Genotyping 542 585 genome-wide single nucleotide polymorphisms was performed in all the patients with Liddle syndrome of the 3 families and some of their relatives. A panel of 780 healthy Italian adult samples typed for the same set of markers was used as controls. espite different lineages between the 3 families based on the analysis of mitochondrial DNA and Y chromosome, the 3 probands and their 6 affected relatives share the same ≈5 Mbp long haplotype which encompasses the mutant allele. Using an approach based on coalescent theory, we estimate that the 3 families inherited the mutant allele from a common ancestor ≈13 generations ago and that such an ancestor may have left ≈20 carriers alive today. The prevalence of Liddle syndrome in the region of origin of the 3 families may be much higher than that estimated worldwide.

Inconsistent genotyping call at DYS389 locus and implications for interpretation.

The male-specific Y chromosome short tandem repeat (STR) locus is used widely in forensic case, which are useful molecular tool to providing the biological evidence for male/female mixture and paternal lineage cases. The Y-STR analysis has been greatly facilitated by advent of commercial multiplex kit. However, even with well-designed robust multiplex kit, abnormal genotyping profile may be observed when encountering with mutations, such as deletion/duplication within the target region or mutation at the primer binding site. In this study, a single-allele shift by five nucleotides for the DYS389I marker between the AmpFlSTR® Yfiler® and Yfiler® Plus PCR amplification kits while the same allele count for DYS389II was observed in eight unrelated Chinese male individuals. After further investigations by re-amplified with three additional multiplex kits, sanger, and next-generation sequencing, the discordance was finally proven caused by existing rare mutation in those sample, which contained two adjacent SNPs only one base apart in the sequence. This paper describes the molecular basis of the discordance at DYS389I genotyping between different commercial multiplex kits and could provide available information for enhancing of interpretation of abnormal Y-STR genotyping in forensic practice.