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.     

Allele frequency distribution of the STR loci HUMTPOX, HUMTH01 and HUMVWA in Asturias (north Spain)

In order to use genetic loci in forensic identity testing, some population data are needed. This paper presents a report of allele frequency data for the loci HUMTH01, HUMTPOX and HUMVWA in a population sample from Northern Spain. No deviation from the Hardy-Weinberg equilibrium was detected in any of the three markers investigated and there was no evidence of association between the alleles of these loci. Statistical analysis was also carried out to obtain some parameters of medicolegal interest and comparative studies were carried out with other populations studied to date for these five loci. The Asturian sample does not differ substantially from other Caucasian and Spanish populations.     

Population genetics of the STR loci HUMCSF1PO, HUMF13A01, HUMFES/FPS and D12S391 in Asturias (northern Spain)

In order to use genetic loci in forensic identity testing, some population data are needed. This paper presents a report of allele frequency data for the loci HUMCSF1PO, HUMF13A01, HUMFES/FPS and D12S391 in a population sample from Asturias (northern Spain).No deviation from the Hardy-Weinberg equilibrium was detected in any of the four markers investigated and there was no evidence of association between the alleles of these loci. Statistical analysis was also carried out to obtain some parameters of medico-legal interest and comparative studies were carried out with other populations studied to date for these loci. The Asturian sample does not differ substantially from other Caucasian and Spanish populations.     

Genetic characterization of an X-STR decaplex on the population of Pichincha (Ecuador)

This study reports data of ten X-STR markers (DXS8378; GATA172D05; DXS6809; DXS7132, GATA31E08, DXS9898, DXS7133, DXS7423, DXS9902, DXS6789) in Ecuadorian population from Pichincha (Sierra Region). To achieve these, we selected 100 non-related individuals that had signed informed consent (48 women and 52 men). They were typified using markers previously described by the Spanish and Portuguese ISFG Working Group (GEP-ISFG, 2008) and following their experimental recommendations.     

Genetic admixture and diversity estimations in the Mexican Mestizo population from Mexico City using 15 STR polymorphic markers

The 15 AmpFlSTR Identifiler loci D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA were analyzed in a sample of 378 unrelated individuals from Mexico City, Mexico. Significant deviations from HW equilibrium in 14/15 STR loci alleles were not detected. The D18S51 locus had the highest power of discrimination (0.970). Genetic admixture estimations revealed a 69% of Amerindian, 26% of European and 5% of African contribution. Comparative analyses between Mexicans and other neighboring populations reveal significant differences in genetic diversity. Our results are important for future comparative genetic studies in different Latin American ethnic groups, particularly Mexican Mestizos and Amerindians. They should also be helpful in genetics, population evolution, forensic and paternity testing.     

Genetic investigation of Chinese she ethnic based on autosomal STRs and X-STRs

The She ethnic is a large minority in China with approximately 700,000 individuals. For more than one thousand years, they mainly resided in Zhejiang and Fujian provinces. To obtain a better understanding of the genetic background of She, we investigate 21 autosomal STRs (A-STRs) and 16 X-STRs in 296 unrelated healthy individuals from Zhejiang She population. Allele frequencies and forensic parameters prove these markers are useful for forensic application. We also investigate the genetic background with the two types of markers. Nei genetic distances between She and Eastern Han population are always the lowest, regardless of the markers used for analysis. Although the tested STRs are located on different chromosomes with different inheritance laws, A-STRs and X-STRs provided in general congruent phylogenetic signal and similar cluster among compared groups. These results demonstrated that geographic isolation and interactions play significant roles in differentiation of genetic constitution of ethnic groups.     

48个X-SNP位点的筛选及法医学应用价值分析

目的对筛选出的48个X-SNP位点进行遗传学分析,评价其法医学应用价值。方法根据NCBI和Hap-Map网站提供的位点信息筛选出48个高信息量X-SNP位点,利用SNPlexTMSystem技术平台进行分型检测,通过中国华东地区汉族人群200个无关个体的调查建立遗传学资料,对48个X-SNP位点的遗传多态性进行研究分析,并进行连锁不平衡检验。结果除rs6527549外,筛选出的48个X-SNP位点在中国华东汉族人群中具有高信息量,多态信息含量均在0.32以上,个体识别率在女性群体和男性群体分别为0.56和0.40以上,非父排除率在二联体和三联体中分别为0.20和0.32以上。检验发现,部分位点存在连锁不平衡现象。结论本实验选取的48个X-SNP位点分型结果稳定,重复性好,在法医生物学研究中具有较高的应用价值,适于开展大规模的高通量检测。     

Development of 30 InDel markers typing system and genetic analysis in five different Chinese populations

Allele frequencies of 30 InDel markers previously selected and validated for forensic purpose were assessed in 419 unrelated individuals originating from five different populations of Chinese Han, Chinese Hui, Uighur, Mongolian and Tibetan in P.R. China. Hardy–Weinberg equilibrium tests and linkage disequilibrium analysis were performed and the results showed that allele frequency distributions of the 30 InDel markers had meet the genetic equilibrium in all of the five populations and the InDel markers on same chromosome did not generate any linkage block. Analysis of molecular variance (AMOVA) indicated that genetic variation among the 5 studied populations represent only 4.00% of the total genetic diversity. We observed the cumulative power of discrimination (CPD) for each studied population was 0.99999999999841 in Chinese Han population, 0.99999999999690 in Chinese Hui population, 0.99999999999709 in Uighur population, 0.99999999999772 in Mongolian population and 0.99999999999854 in Tibetan population.     

STR data for the AmpFℓSTR Identifiler loci from Swedish population in comparison to European, as well as with non-European population

The modern Swedish population is a mixture of people that originate from different parts of the world. This is also the truth for the clients participating in the paternity cases investigated at the department. Calculations based on a Swedish frequency database only, could give us overestimated figures of probability and power of exclusion in cases including clients with a genetic background other than Swedish. Here, we describe allele frequencies regarding the markers in the Identifiler-kit. We have compared three sets of population samples; Swedish, European and non-European to investigate how these three groups of population samples differ. Also, all three population sets were compared to data reported from other European and non-European populations.Swedish allele frequencies for the 15 autosomal STRs included in the Identifiler kit were obtained from unrelated blood donors with Swedish names. The European and non-European frequencies were based on DNA-profiles of alleged fathers from our paternity cases in 2005 and 2006.     

Third molar development according to chronological age in populations from Spanish and Magrebian origin

Spain is frequently the entrance country into the European Union for undocumented immigrants, especially those from the Magreb (Northern Africa). Forensic age estimates for these persons are difficult because systematic studies of dental maturity are lacking. Three different populations were analyzed to determine the pattern of development of third molars as a tool for age estimation in people of different ethnic and geographic origin. Orthopantomograms from two different populations of Spanish origin (Galicia in northwestern continental Spain, and Ceuta, a Spanish province in Northern Africa) were compared to radiographs of molars from a Magrebian population (Northern Africa) resident in Ceuta. Orthopantomograms were obtained from a private dental clinic (n=344) in Galicia and from the Public Oral Health Services (n=228) in Ceuta. We looked for differences in third molar mineralization (determined with the Demirjian scale) that might serve as age indicators (older versus younger than 18 years). Differences in maturation patterns were found between sexes and populations of origin. Mineralization of tooth 38 was more advanced in males than females among subjects 18 years of age and older in all three populations. Moreover, mineralization of tooth 38 in subjects aged 18 years and older was significantly slower in the Spanish-Galicia population than in the Magrebian-Ceuta population. We found no significant differences between Magrebian and Spanish individuals from Ceuta. We conclude that differences in tooth 38 mineralization may be related more with socio-geographical than ethnic origin (ancestry), and thus constitute evidence of the relevance of socio-geographic rather than genetic factors in third molar development. We used ROC analysis to determine the accuracy of the examiner's ability to correctly estimate age as younger or older than 18 years. The results suggest that Demirjian stage for tooth 38 can be considered a good indicator of age in all three populations.     

Topological Variability of Fingerprint Ridge Density in a Sub‐Saharan Population Sample for Application in Personal Identification

Variability in ridge density in a sub‐Saharan population sample was studied by counting ridges in three fingerprint areas (two distal regions, radial and ulnar, and one proximal region) on the epidermal surface of the distal phalanx. Study material was obtained from the fingerprint impressions of 100 male sub‐Saharan subjects aged between 18‐ and 48‐years old. The results were compared with those obtained from a Spanish population sample. Sub‐Saharan males presented lower ridge density than Spanish males in the distal regions (radial and ulnar) of all fingers, whereas differences in the proximal region were only observed on some fingers. Using the differences observed between these populations, the likelihood ratio for inferring membership of one of the populations from a fingerprint of unknown origin was calculated; therefore, a ridge density of 14 or less for both areas (ulnar and radial), support an origin sub‐Saharan versus Spanish population.     

Population data for Southern Spain and Canary Islands of HLADQA1, PM and D1S80 loci

Allele frequencies for seven polymerase chain reaction (PCR)-based DNA genetic markers in two Spanish populations (Southern Spain and Canary Islands), were determined and compared. The loci analysed were HLADQA1, LDLR, GYPA, HBGG, D7S8,Gc, and D1S80.     

Genetic analysis of the Amerindian Kichwas and Afroamerican descendents populations from Ecuador characterised by 15 STR-PCR polymorphisms

Allele frequency data for the 15 STR systems and Amelogenine were determined in a population sample of healthy Amerinidian Kichwas and Blacks individuals. All loci met Hardy-Weinberg expectations and the high discrimination power of combined system showed the forensic efficiency of these genetic markers.     

Genetic analysis of the Amerindian Kichwas and Afroamerican descendents populations from Ecuador characterised by 15 STR-PCR polymorphisms

Allele frequency data for the 15 STR systems and Amelogenine were determined in a population sample of healthy Amerinidian Kichwas and Blacks individuals. All loci met Hardy–Weinberg expectations and the high discrimination power of combined system showed the forensic efficiency of these genetic markers.     

Genetic diversity at 15 fluorescent-labeled short tandem repeat loci in the Patel and other communities of Gujarat, India

Thirteen tetranucleotide and 2 pentanucleotide repeat units were analyzed in 120 unrelated individuals of Patel and other communities of Gujarat, India. Allele frequency data obtained from the analysis of 15 short tandem repeat markers of the population were found to be satisfying Hardy-Weinberg equilibrium, with marginal deviations. Departures from Hardy-Weinberg equilibrium were observed in Patel communities at locus vWA and for that of the other communities at locus D7S820 and at locus TPOX. The power of discrimination values on an average fall within the range of 0.718 and 0.870, with deviations at locus D3S1358 showing a value of 0.400 for Patels. The value ranged between 0.709 and 0.869, with slight variations among the studied alleles in the other group. Thus, the 15 markers selected for this study were found to be highly suitable in human identification and for providing information on genetic polymorphism of the population of Gujarat.     

Evaluation of 15 biparental STR loci in human identification and genetic study of the Kannada-speaking groups of India

Thirteen tetranucleotide and 2 pentanucleotide repeat units were analyzed in 167 unrelated Kannada-speaking individuals belonging to 3 important communities, namely, Kuruva, Bhovi, and Christians, residing in different districts of Karnataka, India. Allele frequency data obtained from the analysis of 15 short tandem report (STR) markers of the subpopulation groups included in the study were observed to be similar, indicating a common ancestry or gene flow among these communities. Departures from Hardy-Weinberg equilibrium were observed in Kuruva population at locus D5S818 and D18S51 and at locus CSF1PO in the Christian community. The data of these communities were analyzed with allele frequency data of 4 other populations from Karnataka, India-Iyengar Brahmin, Gowda, Lingayat, and Muslim-to compute the combined power of discrimination, ranged from 0.962 to 0.974, with negligible difference between populations. The combined power of exclusion, however, remained constant at 0.999 for all populations evaluated in the study. Thus, the 15 markers selected for this study were found to be highly suitable in human identification and for providing information on genetic polymorphism.     

Genetic population data of 38 autosomal InDels for the Amerindian community Embera-Chami of Lapo,Antioquia-Colombia

This paper presents the genetic characterization of the Embera-Chami Amerindian community of Lapo-Antioquia-Colombia using 38 autosomal Indels. This group of markers showed a high discriminatory power (>99.9999%) and an appropriate power of exclusion (99.40%), allowing the use of these markers in the field of forensic genetics in this population.     

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.     

Distribution of HLA DQA1, LDLR,GYPA, HBGG,D7S8, and GC locus alleles in the population of Russia

The distribution of chromosome locus alleles HLA DQA1, LDLR, GYPA, HBGG, D7S8, and GC of PolyMarker molecular genetic individualizing system was studied for the first time in a representative "mean statistical" sampling of Russian population. Typing of these locuses was carried out in 391 donors (no relatives) from 63 regions of the Russian Federation. The incidence of genotypes of all 6 locuses corresponded to the expected values, estimated on the basis of Hardy-Weinberg equilibrium hypothesis. This allows us to use the frequency characteristics of HLA DQA1 locus and the PolyMarker locuses determined in our study as the reference parameters for standard probability estimations in DNA identification. The frequencies of PolyMarker locuses alleles in the Russian sampling (in comparison with other ethnic groups) coincided best of all for allele frequencies in Europeoids living in the USA. For expert evaluation of the efficiency of using these locuses as molecular genetic markers with identification purposes, the discrimination potential was estimated separately for each locus and combinations thereof. HLA DQA1 locus was the most informative of the studied 6 locuses. The main population characteristics of this locus (probability of accidental coincidence, potential of discrimination--PD, polymorphism coefficient--PIC, exclusion potential--Pe, and mean value of parentage index--PI) were estimated for the population of Russia. The frequency distribution of alleles of the studied panel of locuses in the mean statistical Russian population obtained in our study can be used in molecular genetic personality identification and in anthropological studies.     

The forensic DNA implications of genetic differentiation between endogamous communities

In many indigenous minority populations, and among migrants from Asian and African populations now resident in western Europe, North America and Australia, there is a strong tradition of endogamy and a preference for consanguineous unions. These marriage practices can result in F(ST) values greatly in excess of the maximum value (0.01) currently recommended for forensic DNA purposes under guidelines established by the National Research Council (NRC) of the USA. To examine the possible extent of deviation from this accepted norm, three co-resident Pakistani communities were studied using 10 autosomal dinucleotide markers and six tetranucleotide markers on the Y-chromosome. The mean population subdivision coefficient (FST) value was 0.13 for the autosomal loci, and Y-chromosome loci exhibited even stronger differentiation with unique alleles identified in all three communities. The data indicate that even when sub-populations are virtually indistinguishable in terms of anthropology, geography, ethnicity or culture, they may still exhibit major genetic differentiation. Where significant population stratification is known to exist, more detailed genetic databases should be developed for forensic DNA purposes, based on reference data from each of the appropriate sub-populations and not on random or combined samples.