Validation of the X-linked STR DXS6801

This paper presents sequence and population genetic data of the X-linked microsatellite marker DXS6801 (GDB:G00-365-276) which is a tetranucleotide repeat polymorphism representing eight alleles 109-141 bp in length. Data were obtained from a sample of 1146 unrelated German individuals. DXS6801 is located 99.7 cM from Xptel, nearby DXS6809 [Int. J. Legal Med. 117 (2003) 241] and DXS6789 [Forensic Sci. Int. 119 (2001) 42] in Xq21. The new marker could be added to the panel of ChrX STRs, especially usable as a part of the Xq21 linkage group.     

Sequence variation and allele nomenclature for the X-linked STRs DXS9895, DXS8378, DXS7132, DXS6800, DXS7133, GATA172D05, DXS7423 and DXS8377

X-linked DNA markers are increasingly used in forensic kinship testing. This paper presents sequencing data of the short tandem repeats (STRs) DXS9895, DXS8378, DXS7132, DXS6800, DXS7133, GATA172D05, DXS7423, DXS8377 and proposes an allele nomenclature. Alleles were assigned according to the recommendations of the International Society of Forensic Genetics (ISFG) Commission.     

Validation of the STR DXS7424 and the linkage situation on the X-chromosome

X-linked microsatellite markers have proven to be powerful tools for parentage testing, mainly in deficiency paternity cases when the disputed child is female. However, only a small number of X-linked short tandem repeats (STRs) have been comprehensively described for forensic applications to date.We present sequence and population genetic data of the DXS7424 STR (GDB-G00-577-633) which is a trinucleotide repeat polymorphism representing 12 alleles of 147-180 bp in length. DXS7424 is located at Xq22 and closely linked to DXS101, corresponding to a genetic localisation of 104.9-121 cM from Xp-tel.PCR fragment length measurements and sequencing were carried out using the automatic gene analyser ABI 310 (Applied Biosystems).The population of 764 unrelated Germans checked for this STR exhibited the following features: polymorphism information content (PIC) = 0.780; heterozygosity (Het) = 0.843; mean exclusion chance (MEC = 0.766. Kinship tests revealed a typical X-linked inheritance. In 300 meioses under investigation, mutations were not found. Significant deviations from the Hardy-Weinberg equilibrium (HWE) were not established.Linkage studies confirmed closely linkage to DXS101. Additional we found linkage disequilibrium between DXS7424 and DXS101. This requires to use the established haplotype frequencies in kinship testing.     

Polymorphism of four X-chromosomal STRs: DXS7423, DXS7424, DXS8378 and DXS6809 in a North Italian population sample and their use in kinship testing

The present study analyses three tetranucleotide (DXS7423, DXS8378, DXS6809) and one trinucleotide (DXS7424) X-linked STRs loci in a population sample of North Italy to evaluate their efficiency in forensic applications. The four loci were also used to solve a case of deficiency paternity, in which the question was to establish whether two women were half sisters.     

Genetic data of 10 X-STRs in a Spanish population sample

In this work, we present population genetic data of 10 X-chromosome STRs (DXS8378, DXS9898, DXS8377, HPRTB, GATA172D05, DXS7423, DXS6809, DXS7132, DXS101 and DXS6789) obtained from sample of 145 unrelated female individuals belonging to Valencia (Spain), a region located in the east of the Iberian Peninsula. All the markers studied present high genetic diversities, similar to those previously reported in other European population samples. No deviations from Hardy-Weinberg equilibrium were observed, with the exception of DXS101 locus. Allele frequencies and parameters of forensic interest for each X-STR were calculated. High mean exclusion chance and power of discrimination values were obtained by combining these 10 X-linked markers. Population comparisons (exact test of population differentiation; pairwise genetic distances) were carried out and low genetic distances were found between our sample and those from other Spanish or European regions.     

中国鄂温克族DXS7423，DXS7424，DXS7132，DXS7133，DXS6804位点多态性的研究

目的以无关个体为研究对象,研究鄂温克族人群X染色体5个STR位点的遗传多态性,建立群体遗传数据库。方法用聚合酶链反应(PCR)、变性聚丙烯凝胶电泳和银染的方法,检测98名中国鄂温克族DXS7423,DXS7424,DXS7132,DXS7133,DXS6804位点的重复序列长度的变化。结果5个STR位点在鄂温克族群体均具有遗传多态性,χ2检验表明多态性分布符合Hardy-Weinberg平衡定律。结论中国鄂温克族X染色体5个STR基因座群体遗传数据资料,可用于法庭科学个体识别、亲子鉴定及其他人类学研究。     

Population data of eight X-chromosomal STR markers in Ewe individuals from Ghana

The investigation of the X-linked DNA markers are well established in the forensic routine case work. We studied an Ewe population sample from Ghana. The eight X-chromosomal STRs DXS10135, DXS8378, DXS7132, DXS10074, HPRTB, DXS10101, DXS10134 and DXS7423 were analyzed in 182 Ewe individuals (108 females and 74 males) from the region of Sogakofe (Ghana). Allele frequencies and statistical parameter as well as comparison with known data from Germans and with data from an Amharic population (Ethiopia) are presented.     

Allele frequencies and haplotypes of eight Y-short tandem repeats in Bantu population living in Central Africa

Eight Y chromosome short tandem repeats (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385I/II) were used to assess haplotype distribution in non-selected, unrelated Bantu males living in Central Africa [N. Mathias, M. Bayes, C. Tyler-Smith, Highly informative compound haplotypes for the human Y chromosome, Hum. Mol. Genet. 3 (1994) 115-123; L. Roewer, J. Arnemann, N.K. Spurr, K.H. Grzeschik, J.T. Epplen, Simple repeat sequences on the human Y chromosome are equally polymorphic as their autosomal counterparts, Hum. Genet. 89 (1992) 389-394; P. De Knijff, M. Kayser, A. Caglia, D. Corach, N. Fretwel, C. Gehrig, G. Graziosi, F. Heidorn, S. Herrmann, B. Herzog, M. Hidding, K. Honda, M. Jobling, M. Krawczak, K. Leim, S. Meuser, E. Meyer, W. Oesterreich, A. Pandya, W. Parson, G. Penacino, A. Perez-Lezaun, A. Piccini, M. Prinz, C. Schmitt, P. M. Schneider, R. Szibor, J. Teifel-Greding, G. Weishold, L. Rower, Chromosome Y microsatellites: population genetic and evolutionary aspects, Int. J. Legal Med. 110 (1997) 134-149; M. Kayser, A. Caglia, D. Corach, N. Fretwel, C. Gehrig, G. Graziosi, F. Heidorn, S. Herrmann, B. Herzog, M. Hidding, K. Honda, M. Jobling, M. Krawczak, K. Leim, S. Meuser, E. Meyer, W. Oesterreich, A. Pandya, W. Parson, G. Penacino, A. Perez-Lezaun, A. Piccini, M. Prinz, C. Schmitt, P. M. Schneider, R. Szibor, J. Teifel-Greding, G. Weishold, P. de Knijff, L. Rower, Evaluation of Y chromosome STRs: a multicenter study, Int. J. Legal Med. 110 (1997) 125-133, 141-149]. One hundred and sixty-five full haplotypes were obtained from Bantu males. The most common haplotype (DYS19-15, DYS389I-13, DYS389II-30, DYS390-21, DYS391-10, DYS392-11, DYS393-13, DYS385I/II-15,17) was shared by 5.5% of individuals. In the Bantu population in Central Africa, the haplotype diversity and the discrimination capacity of Y-STR may be estimated at 99.14% and 0.5333, respectively.     

广东汉族DXS10011和DXS8377单体型

目的调查DX10011和DXS8377两个X染色体STR在广东汉族男性群体中的遗传多态性。方法DNA样本来自广东汉族男性无关个体,PCR后用聚丙烯酰胺凝胶电泳和银染法进行DNA分型。结果在113名个体中,DXS10011和DXS8377分别检出20和12个等位基因。DXS10011-DXS8377共有72种不同的单体型,最多见的单体型只出现了3次。在没有母亲时,DXS10011-DXS8377的女孩的非父排除率为0.9588。在83个孩子为女孩的三联体家系和29个有两个孩子的家系中,DXS10011和DXS8377均表现为共显性连锁遗传,且没有发现突变。结论本数据表明DXS10011和DXS8377在复杂的亲权鉴定中可提供高的遗传多态性信息。     

Population genetic study in two Transylvanian populations using forensically informative autosomal and Y-chromosomal STR markers

Our study provides population genetic data on two population samples collected in a Hungarian speaking region of Transylvania, Romania. Allele frequency and profile databases were generated on 17 autosomal STR loci (D2S1338, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D19S433, D21S11, VWA, FGA, TH01, TPOX, CSF1PO, Penta E and Penta D) as well as at the 12 European Y-STR extended haplotype loci (DYS19, DYS389-I/II, DYS390, DYS391, DYS392, DYS393, DYS385 loci, DYS437, DYS438 and DYS439). Data were compared to a Central Hungarian (Budapest region) population sample [B. Egyed, S. Füredi, M. Angyal, L. Boutrand, A. Vandenberghe, J. Woller, Z. Padar, Analysis of eight STR loci in two Hungarian populations, Forensic Sci. Int. 113 (2000) 25-27] that was used as a reference group of the Hungarian population. Calculating the F(ST) indices and with the pairwise comparisons of interpopulation molecular variance (AMOVA) the two populations from Transylvania could be fit into the Hungarian population data showing less substructuring effects as compared to the previous findings in Hungary [B. Egyed, S. Füredi, M. Angyal, L. Boutrand, A. Vandenberghe, J. Woller, Z. Padar, Analysis of eight STR loci in two Hungarian populations, Forensic Sci. Int. 113 (2000) 25-27; B. Egyed, S. Füredi, M. Angyal, I. Balogh, L. Kalmar, Z. Padar, Analysis of the population heterogeneity in Hungary using fifteen forensically informative STR markers, Forensic Sci. Int. 158 (2005) 244-249].     

Genetic analysis of 18 X-linked short tandem repeat markers in Korean population

The population genetic data of 18 X-chromosomal short tandem repeat (STR) markers DXS6807, DXS8378, DXS9895, DXS9902, DXS6810, DXS7132, DXS981, DXS6800, DXS9898, DXS6789, DXS101, DXS6797, GATA172D05, GATA165B12, HPRTB, GATA31E08, DXS8377, and DXS7423 were analyzed in samples of unrelated 220 males and 181 females from Korean population. The exact test for genotype distribution of the markers showed no significant deviation from the Hardy-Weinberg equilibrium. Allele frequencies between male and female samples were not significantly different in all examined markers. All examined males and females showed different hemizygotic haplotype and combined genotypes, respectively. Four cases of mutation were found in GATA172D05, GATA31E08, DXS7132, and HPRTB from the analysis of 95 father-child-mother trios. Details of X chromosomal STRs in Koreans would be useful in paternity tests and forensic purposes as well as whole X-chromosomal mapping studies.     

Four X-chromosomal STRs and their allele frequencies in a Chinese population

X-chromosomal markers are particularly useful for solving complex problems relating to kinship and deficiency paternity analysis. In the present study, population genetics data of four X-chromosomal short tandem repeats (STRs) DXS8378, HPRTB, DXS7423 and DXS7132 were obtained by analyzing 500 unrelated Chinese individuals (250 males and 250 females). Population genetics data obtained from the Chinese were compared with those of the Asian and European population. Mutations in X-chromosomal markers were analyzed based on a total of 61 proven father-child and 45 proven mother-child pairs.     

Genetic Polymorphisms of four X-STR Loci: DXS6797, DXS6800, HPRTB and GATA172D05 in a Peruvian population sample

The X linked short tandem repeats (STR) markers have proven to be very useful tools for paternity testing when the disputed child is female. The purpose of this study was to describe the genetic polymorphism of four X-chromosomal STR loci (DXS6797, DXS6800, HPRTB and GATA172D05) in a Peruvian population sample and evaluate their efficiency in forensic practice and paternity testing.     

How reliable is the sub-population model in DNA testimony?

The performance of the sub-population model first proposed by Balding and Nichols [D.J. Balding, R.A. Nichols, DNA profile match probability calculation: how to allow for population stratification, relatedness, database selection and single bands. Forensic Sci. Int. 64 (1994) 125-140] is examined using a simulation approach. This work extends the investigations of Curran et al. [J.M. Curran, J.S. Buckleton, and C.M. Triggs, What is the magnitude of the sub-population effect? Forensic Sci. Int. 135 (2003) 1-8]. In particular the effect of underestimating the coancestry coefficient, theta, and the effect of departures from the modelling assumptions were investigated. The model tends to give strongly conservative estimates if the estimate for the coancestry coefficient is accurate. If this coefficient is underestimated then a larger fraction of cases give non-conservative estimates. Departures from the modelling assumption that the sub-population is in Hardy-Weinberg and linkage equilibria appear to have very little effect.     

Development of two pentaplex systems with X-chromosomal STR loci and their allele frequencies in a northeast German population

In this study we present two new pentaplex systems for the coamplification of X-chromosomal short tandem repeats (STRs). X-penta-1 comprises DXS9898, DXS6807, HPRTB, DXS101, and androgen receptor (ARA); X-penta-2 consists of DXS7133, DXS10011, DXS7424, DXS8377, and DXS8378. In addition, allele frequencies for these loci in a northeast German population comprising 100 females and 105 males were shown. The applicability and usefulness of our two PCR pentaplex approaches in paternity deficiency cases is demonstrated by a combined power of discrimination (PD(c)) for both females and males with PD(c)>0.999999.     

Analysis of global variability in 15 established and 5 new European Standard Set (ESS) STRs using the CEPH human genome diversity panel

The CEPH human genome diversity cell line panel (CEPH-HGDP) of 51 globally distributed populations was used to analyze patterns of variability in 20 core human identification STRs. The markers typed comprised the 15 STRs of Identifiler, one of the most widely used forensic STR multiplexes, plus five recently introduced European Standard Set (ESS) STRs: D1S1656, D2S441, D10S1248, D12S391 and D22S1045. From the genotypes obtained for the ESS STRs we identified rare, intermediate or off-ladder alleles that had not been previously reported for these loci. Examples of novel ESS STR alleles found were characterized by sequence analysis. This revealed extensive repeat structure variation in three ESS STRs, with D12S391 showing particularly high variability for tandem runs of AGAT and AGAC repeat units. The global geographic distribution of the CEPH panel samples gave an opportunity to study in detail the extent of substructure shown by the 20 STRs amongst populations and between their parent population groups. An assessment was made of the forensic informativeness of the new ESS STRs compared to the loci they will replace: CSF1PO, D5S818, D7S820, D13S317 and TPOX, with results showing a clear enhancement of discrimination power using multiplexes that genotype the new ESS loci. We also measured the ability of Identifiler and ESS STRs to infer the ancestry of the CEPH-HGDP samples and demonstrate that forensic STRs in large multiplexes have the potential to differentiate the major population groups but only with sufficient reliability when used with other ancestry-informative markers such as single nucleotide polymorphisms. Finally we checked for possible association by linkage between the two ESS multiplex STRs closely positioned on chromosome-12: vWA and D12S391 by examining paired genotypes from the complete CEPH data set.     

Genetic data of 10 X-STRs in a population sample from Lima,Perú

Genetic population data for 10 X-STR (DXS6789, DXS9902, DXS7132, GATA31E08, DXS7133, DXS9898, DXS8378, DXS6809, DXS7423 and GATA172D05) were obtained from Lima population. The present study results support the usefulness of these markers in kinship investigation and also in population genetics studies.     

Development of the X-linked tetrameric microsatellite markers HumDXS6803 and HumDXS9895 for forensic purpose

This paper presents sequence and population genetic data of the X-linked DXS6803 and DXS9895 short tandem repeat (STR). The tetranucleotide repeat polymorphism DXS6803 (also known as CHLC.GATA45H11) and DXS9895 (also known as CHLC.GATA124B04) are located at the Xq12-Xq21.33 and Xpter-Xp22.2 region, respectively. In kinship testing, DXS6803 and DXS9895 are suitable for concomitant use. Population genetic data were obtained by analyzing 182 unrelated females and 110 males from Chinese Han population. In this population, both DXS6803 and DXS9895 exhibited seven clearly distinguishable alleles ranging from 109bp to 128bp and 139bp to 163bp in length, respectively. Testing for Hardy-Weinberg equilibrium (HWE) showed no significant deviation for these two loci. The polymorphism information content (PIC), observed heterozygosity (H(obs)) and power of exclusion for parentage testing of a girl for trios (PE(trio)) and duos (PE(duo)) were 0.67, 0.687, 0.673 and 0.530 for DXS6803, and 0.69, 0.736, 0.688 and 0.547 for DXS9895, respectively. Seventy-eight families studies of these two loci confirmed X-linked codominant inheritance and mutations were not found.     

LoComatioN: a software tool for the analysis of low copy number DNA profiles

Previously, the interpretation of low copy number (LCN) STR profiles has been carried out using the biological or 'consensus' method-essentially, alleles are not reported, unless duplicated in separate PCR analyses [P. Gill, J. Whitaker, C. Flaxman, N. Brown, J. Buckleton, An investigation of the rigor of interpretation rules for STRs derived from less than 100 pg of DNA, Forens. Sci. Int. 112 (2000) 17-40]. The method is now widely used throughout Europe. Although a probabilistic theory was simultaneously introduced, its time-consuming complexity meant that it could not be easily applied in practice. The 'consensus' method is not as efficient as the probabilistic approach, as the former wastes information in DNA profiles. However, the theory was subsequently extended to allow for DNA mixtures and population substructure in a programmed solution by Curran et al. [J.M. Curran, P. Gill, M.R. Bill, Interpretation of repeat measurement DNA evidence allowing for multiple contributors and population substructure, Forens. Sci. Int. 148 (2005) 47-53]. In this paper, we describe an expert interpretation system (LoComatioN) which removes this computational burden, and enables application of the full probabilistic method. This is the first expert system that can be used to rapidly evaluate numerous alternative explanations in a likelihood ratio approach, greatly facilitating court evaluation of the evidence. This would not be possible with manual calculation. Finally, the Gill et al. and Curran et al. papers both rely on the ability of the user to specify two quantities: the probability of allelic drop-out, and the probability of allelic contamination ("drop-in"). In this paper, we offer some guidelines on how these quantities may be specified.     

Allele distribution of three X-chromosome STR loci in an antioquian population sample

The X-linked short tandem repeats (STR) markers have proven to be very useful tools for paternity testing when the disputed child is female. The aim of this study was to describe the polymorphism of three X-chromosomal STR loci (DXS6797, DXS6800 and HPRTB) in an Antioquian (Colombian) population sample. PCR products were separated in 4% acrylamide-bis-acrylamide denaturing gels followed by silver staining. Allele size determination and genotyping were performed according to recommendations of the DNA Commission of the International Society of Forensic Genetic using the allelic ladder manufactured at home and based on DNA controls including K562 and 9947A (Promega). Gene frequencies were calculated using ARLEQUIN version 3.11. Population genetic data were obtained by analyzing 127-400 unrelated males and 135 unrelated females from Antioquian (Colombian) population. Distribution of the allele frequencies of these systems for Antioquia population is similar to the European populations.