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 variation at six STR loci (HUMTH01, HUMTPOX, HUMCSF1PO, HUMF13A01, HUMFES/FPS, HUMVWFA31) in Aragon (north Spain).

The STR loci HUMTH01, HUMPTPOX, HUMCSF1PO, HUMF13A01, HUMFES/FPS and HUMVWFA31 are widely used in forensic casework analyses and population data are necessary to estimate the frequency of a DNA profile. This paper presents the results of a survey aimed to investigate the allele frequency distribution of these loci in an important Spanish population (Aragon, North Spain). Statistical analysis to determine whether allele frequencies were in Hardy-Weinberg Equilibrium was carried out and also to obtain some parameters of medico-legal interest. There was no evidence of association between the alleles of the loci. The Aragonese sample does not differ substantially from other Caucasian populations.     

Allele frequencies of 15 short tandem repeats (STRs) in three Egyptian populations of different ethnic groups

DNA typing of 15 short tandem repeat (STR) loci included in the AmpFlSTR Identifiler PCR amplification kit (Applied Biosystems), was carried out in three Egyptian populations of different ethnic groups: the Berbers from the Siwa oasis (in the North-Western Egyptian desert), the Muslims and the Copts from Adaima (Upper Egypt). A total of 297 individuals were typed. After Bonferroni's correction, no deviations from the Hardy-Weinberg equilibrium were observed for all samples at the 15 STR loci. All loci are highly polymorphic and population differentiation tests showed that 7, 10 and 8 out of 15 loci have significant differences between the Berbers and the Muslim samples, between the Berbers and the Copts, and between the two samples from Adaima, respectively. Comparative analyses between our population data and other geographically related populations gathered from the literature were performed.     

Distribution of the HLA-DQA1 and polymarker alleles in the Basque population of Spain

HLA-DQA1 and polymarker (LDLR, GYPA, HBGG, D7S8, and GC) genotypic and allelic frequencies are determined for a population sample of 102 unrelated Basque individuals using PCR-based methodology. All six loci met Hardy-Weinberg expectations in at least two of the three analyses performed (HLA-DQA1 failed to meet Hardy-Weinberg requirements in the heterozygote deficiency test). Three linkage analysis programs (GDA, GENEPOP and LINKDOS) detected possible linkage disequilibrium between LDLR and HBGG and results from one (GDA) indicated a possible non-random association between HBGG and HLA-DQA1 as well. Allelic data for the six loci are compared to that previously established for other populations (18 for polymarker alone, 16 for polymarker plus HLA-DQA1) to determine homogeneity between the Basque sample and these groups. According to the results of G-tests based on these loci, the Tadjik, a nomadic Caucasian group from western Asia, and the Basque residents are the only sample populations surveyed that are homogenous with the Basque sample. Phylogenetic analysis places the Basque sample correctly within the Caucasian cluster.     

Results of the GEP-ISFG collaborative study on the Y chromosome STRs GATA A10, GATA C4, GATA H4, DYS437, DYS438, DYS439, DYS460 and DYS461: population data

The Spanish and Portuguese ISFG Working Group (GEP-ISFG) carried out a collaborative exercise in order to asses the performance of two Y chromosome STR tetraplexes, which include the loci DYS461, GATA C4, DYS437 and DYS438 (GEPY I), and DYS460, GATA A10, GATA H4 and DYS439 (GEPY II). The groups that reported correct results in all the systems were also asked to analyse a population sample in order to evaluate the informative content of these STRs in different populations. A total of 1020 males out of 13 population samples from Argentina, Brazil, Costa Rica, Macao, Mozambique, Portugal and Spain were analysed for all the loci included in the present study. Haplotype and allele frequencies of these eight Y-STRs were estimated in all samples. The lowest haplotype diversity was found in the Lara (Argentina) population (95.44%) and the highest (99.90%) in Macao (China). Pairwise haplotype analysis showed the relative homogeneity of the Iberian origin samples, in accordance with what was previously found in the European populations for other Y-STR haplotypes (http://www.ystr.org). As expected, the four non-Caucasian samples, Macao (Chinese), Mozambique (Africans), Costa Rica (Africans) and Argentina (Lara, Amerindians), show highly significant Phist values in the pairwise comparisons with all the Caucasian samples.     

Analysis of 16 Y STR loci in the Finnish population reveals a local reduction in the diversity of male lineages

We analysed samples of 400 Finnish males using nine Y-chromosomal short tandem repeat (STR) loci (minimal haplotype); for 200 of these subjects an additional seven Y-chromosomal STR loci were used. The geographical distribution of the observed haplotypes was determined from 200 individuals of known paternal origin within Finland. The observed number of alleles varied from 2 to 13 alleles per locus. A total of 146 minimal haplotypes were identified in our population sample. Interestingly, 90 (22.5%) individuals shared an identical haplotype. This haplotype was extremely frequent in the northern and eastern subpopulations of Savo, Pohjanmaa and Karjala (53, 42 and 37%, respectively). With the seven additional loci analysed in the sample of 200 individuals, 120 haplotypes were identified, and individuals sharing the most common haplotype decreased to 13.0%. However, in comparison to other European populations, the Finnish population showed decreased genetic diversity (GD) when the number of different minimal haplotypes in the population was divided by the sample size (36.5% in Finns versus 83.7% on average). Our results strongly support the earlier hypothesis of individual isolated Y-chromosomal lineages and population substructuring in Finland. For paternity testing, power of exclusion was 92% using minimal haplotype data, but including the seven additional loci this value increased to 97%.     

15 STR loci frequencies in the population from Santa Catarina, Southern Brazil

Allele frequencies for 15 short tandem repeats (STR) loci were determined with a sample of 3000 unrelated individuals from the population of Santa Catarina, Southern Brazil. The loci are most commonly used in forensic and paternity testing, being analyzed by the Powerplex 16 (Promega) commercial kit. The data shows that most polymorphic loci were Penta E and FGA. The distributions of the genotypes in the evaluated loci are in Hardy–Weinberg equilibrium. Comparative analyses between our population data and other Brazilian populations are presented. The calculated forensic parameters showed that the loci are useful for the solution of forensic problems in Brazilian Southern region.     

Population genetics of the D1S1656, D12S391, and D18S535 loci in Asturias (North Spain)

Allele and genotype frequencies for three recently described short tandem repeat loci D1S1656, D12S391, and D18S535 were determined in a population sample from Asturias (North Spain). The loci were amplified using a fluorescence based PCR method and were typed automatically. No deviation from Hardy-Weinberg expectations were observed. The three loci proved to be highly discriminating and the allele frequencies observed are similar to those of the other European populations that have been typed for these loci to date.     

The Upper Silesia (Poland) population and forensic usefulness of 15 autosomal STR loci

Allele frequencies, forensic parameters for the 15 STR loci in the AmpFlSTR^® Identifiler Kit (Applied Biosystems), D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D19S433, VWA, TPOX, D18S51, D5S818 and FGA were determined in a sample of 150 unrelated dead and alive adults from the Upper Silesia region (Poland). The values of heterozygosity (Ht), polymorphic information content (PIC), power of discrimination (PD), matching probability (PM), mean exclusion chance (MEC) and mean exclusion probability (MEP) were calculated. Possible divergence from HWE was determined. Comparison of allele frequencies for examined STR loci between the Upper Silesia population and other Polish populations was carried out.     

Results of a collaborative study of the EDNAP group regarding the reproducibility and robustness of the Y-chromosome STRs DYS19, DYS389 I and II, DYS390 and DYS393 in a PCR pentaplex format

A collaborative exercise was carried out by the European DNA Profiling Group (EDNAP) in the frame work of the STADNAP program, i.e. standardization of DNA profiling in Europe, in order to evaluate the performance of a Y-chromosome STR pentaplex, which includes the loci DYS19, DYS389 I and II, DYS390 and DYS393 and to determine whether uniformity of results could be achieved among different European laboratories.Laboratories were asked to analyze the five Y-STRs using singleplex and multiplex conditions in three bloodstains and one mixed stain (95% female and 5% male).All the laboratories reported the same results even for the mixed stain included in the exercise. This demonstrates the reproducibility and robustness of Y-chromosome STR typing even with multiplex formats and proves the usefulness of Y-STR systems for analyzing mixed stains with a male component.A total of 930 male samples from 10 different populations from Europe were also analysed for all the loci included in the pentaplex. Eight of these ten populations also included haplotype data.As for single gene analysis, haplotype diversity was higher in Germany and Italy and lower in Western European countries and Finland.Pairwise haplotype analysis shows the Finnish departure from the rest of the populations and a relatively homogeneity in the other European populations with F(ST) estimates lower than 0.05.UPGMA analysis shows an association of Western European population (Ireland, UK, Portugal and Galicia) on the one hand and central European populations on the other.     

Data for 10 autosomal STR markers in South Tunisian population

Allele frequencies, together with some parameters of forensic interest for 10 STRs (D3S1358, vWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01 and FGA) were estimated from 201 unrelated individuals originating from southern Tunisia. Significant deviation from Hardy-Weinberg equilibrium was observed for only one marker. Comparative analyses between our population data and other populations showed that only markers D3S158, vWA and FGA were homogenous among populations. The combination of these 10 STR loci provide a powerful tool for forensic identification in Tunisian population.     

Population genetics of nine short tandem repeat loci: allele frequency distribution in a Brazilian population sample

Gene and genotype frequencies in relation to the D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, and D7S820 loci were determined in a sample of 290 unrelated individuals (204 Caucasians and 86 mulattoes) living in the city of S?o Paulo, Brazil. The sex test Amelogenin was also performed in all subjects from our sample, revealing the expected sex in all instances. Allele frequency data obtained from the analysis of these samples were in the usual range of other population groups with similar racial background. In the sample of Caucasian individuals, panmictic proportions were ruled out in relation to TPOX and CSF1PO loci, but only in the latter was the overall frequency of heterozygotes significantly less than expected. In the sample of mulattoes, Hardy-Weinberg proportions were rejected in relation to FGA and CSF1PO loci, but in no instance were the overall numbers of heterozygotes different from the corresponding expected ones under panmixia. Taking into account all this and also the number of tests performed, the degree of genetic heterogeneity of Brazilian populations, and the critical level reached by the significant results (1% < alpha<5%), the departures from panmixia here observed can be considered to be negligible in altering significantly biologic relationship odds calculated under the assumption of random matings.     

Population data on the thirteen CODIS core short tandem repeat loci in African Americans, U.S. Caucasians, Hispanics, Bahamians, Jamaicans, and Trinidadians

Allele distributions for 13 tetrameric short tandem repeat (STR) loci, CSF1PO, FGA, TH01, TPOX, VWA, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, and D21S11, were determined in African American, United States Caucasian, Hispanic, Bahamian, Jamaican, and Trinidadian sample populations. There was little evidence for departures from Hardy-Weinberg expectations (HWE) in any of the populations. Based on the exact test, the loci that departed significantly from HWE are: D21S11 (p = 0.010, Bahamians); CSF1PO (p = 0.014, Trinidadians); TPOX (p = 0.011, Jamaicans and p = 0.035, U.S. Caucasians); and D16S539 (p = 0.043, Bahamians). After employing the Bonferroni correction for the number of loci analyzed (i.e., 13 loci per database), these observations are not likely to be significant. There is little evidence for association of alleles between the loci in these databases. The allelic frequency data are similar to other comparable data within the same major population group.     

Jewish population genetic data in 20 polymorphic loci

Frequency data of 20 polymorphisms (13 autosomal and 6 Y-chromosome STRs and the Alu-insertion YAP) were determined in a sample of 124 unrelated Jewish individuals from Ashkenazi, Sephardic, North African and Oriental origin. The a priori statistical power of the set of studied loci was highly discriminating (PD=1 in 2.393 E+15 individuals for autosomal STRs, and a probability of finding two unrelated males with the same haplotype of less than 0.01). Some significant population differences were registered between Jews and other Circummediterranean populations in Y-chromosome loci frequencies.     

Population frequency distribution of HumF13A01, HumFXIIIB, and HumLIPOL loci in the Basque Country (Northern Spain)

A population study of unrelated individuals from the Basque Country (Northern Spain) was carried out using the GenePrint STR System. The PCR products were separated on denaturing polyacrylamide gels and visualized by silver staining. Three tetrameric loci were evaluated: HumF13A01, HumFXIIIB, and HumLIPOL. All loci fit Hardy-Weinberg expectations, and independence of alleles was found between these STR loci. A comparison with other population groups indicated allele frequencies are well conserved in Caucasians, but differ from other racial groups. The calculated parameters a priori probability of exclusion (Pex) and "power of discrimination" (PD) show how informative these loci are for the determination of identity and relatedness of individuals.     

16 STR data of a Greek population

Allele frequencies for 16 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, FGA, and SE33) were calculated for a sample of 300 unrelated individuals from Greece. No deviations from Hardy–Weinberg equilibrium were observed for all loci. The combined power of discrimination (PD) and the combined power of exclusion (PE) for the 16 tested STR loci were 0.999999999 and 0.999999816, respectively. Population comparisons were carried out and low genetic distances were found between our data and those previously published for other neighbouring European populations.     

Population genetic data of 15 tetrameric short tandem repeats (STRs) in Berbers from Morocco

The allele frequency distribution of 15 short tandem repeats (STR) loci contained in the AmpFlSTR Identifiler PCR Amplification Kit (Applied Biosystems), was determined in two Berber populations from Asni and Bouhria, in Central and Eastern Morocco, respectively. A total of 209 individuals were typed. No deviations from the Hardy-Weinberg equilibrium were observed for Asni at the 15 STRs loci whereas for the Bouhria samples, two loci (D5S818 and TH01) showed significant departures from Hardy-Weinberg expectations (after Bonferroni's correction). All loci are highly polymorphic and population differentiation tests showed that the Moroccan samples from Asni and Bouhria have significant differences in 4 out of 15 loci (D21S11, D7S820, D16S539 and TPOX). The aim of the study was to obtain accurate allele frequencies relevant for forensic applications. Comparative analyses between our population data and other population samples gathered from the literature are also presented.     

Mutation rates at 14 STR loci in the population from Pernambuco, Northeast Brazil

Definition about mutation rates of short tandem repeats (STRs) loci used in forensic analysis are useful for the correct interpretation of resulting genetic profiles and the definition of criterions for exclusion in paternity testing. Germline mutation of 14 STR loci was studied for 54,105 parent–child allelic transfers from 2575 paternity testing cases carried out during 2000–2007 from the Pernambuco State, Northeast Brazil. The parenthood in each of these cases was highly validated (probability > 99.99%). We identified 43 mutations at 12 loci. Locus-specific mutation rate estimates varied between 2 × 10⁻⁴ and 2 × 10⁻³, and the overall mutation rate estimate was 8 × 10⁻⁴. Mutation events in the male germline were more frequent than in the female germline. The majority of the mutations could be explained by losses or gains of one repeat unit and there was no evidence for selection between insertion or deletion changes. Our data were compared with those of Portuguese and North-American populations for CSF1PO, D18S51, D21S11, D7S820, TH01, TPOX and demonstrated, despite the great difference in the size of the sample, that mutation rates of STR loci in a mixed population do not differ from that encountered in different populations.     

Allele frequencies and population data for 17 Y-chromosome STR loci in a Serbian population sample from Vojvodina province

Seventeen Y-chromosomal STR (short tandem repeat) loci were analyzed in a group of 185 healthy unrelated male individuals (n=185) from the population of Serbian province of Vojvodina. After minimal haplotype STR loci analysis we observed 129 different haplotypes. The most frequent haplotype was found in 13 copies, and total haplotype diversity was 99.11%. After analysis of additional eight Y-STR loci (DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and YGATAH4) there were 176 different haplotypes observed, out of which 168 appeared in single copies, and 7 haplotypes appeared twice. The most frequent haplotype was found in three copies. The haplotype diversity (99.94%) and discrimination capacity (95.13%) were calculated. Comparisons were made with previously published haplotype data on neighbouring population samples and significant differences were demonstrated at DYS19, DYS389II and DYS393 loci. Pairwise comparison of populations revealed that our sample was significantly different only from Hungarian sample (RST=23.98%, p=0.0091).     

Thousands of years of Malay and Chinese population history in Indonesia and its implication on Paternity Index in DNA paternity testing

The existence of the Chinese population in the predominantly Malay population in Indonesia can be traced back thousands of years, and it has been suspected that it played an essential role in the history of the Malay population origin in Maritime South East Asia. With the fact that the Malay-Indonesian population is currently predominant compared to the Chinese population in Indonesia (Chinese-Indonesian), the selection of the origin of the STRs allele frequency panel population becomes an issue in DNA profiling, including in paternity testing. This study analyses the genetic relationship between the Chinese-Indonesian and Malay-Indonesian populations and how this affects the Paternity Index (PI) ??calculation in paternity test cases. The study of the relationship between populations was carried out using neighbour-joining (NJ) tree analysis and multidimensional scaling (MDS) on the allele frequency panel of 19 autosomal STRs loci of Malay-Indonesian (n = 210) and Chinese-Indonesian (n = 78) populations. Four population groups were used as references: Malay-Malaysian, Filipino, Chinese, and Caucasian. An MDS analysis was also performed based on the pairwise F_ST calculation. The combined Paternity Index (CPI) calculation was carried out on 132 paternity cases from the Malay-Indonesian population with inclusive results using a panel of allele frequencies from the six populations. The pairwise F_ST MDS indicates a closer relationship between the Chinese-Indonesian and Malay-Indonesian compared to the Chinese population, which is in line with the CPIs comparison test. The outcome suggests that the alternative use of allele frequency database between Malay-Indonesian and Chinese-Indonesian for CPI calculations is not very influential. These results can also be considered in studying the extent of genetic assimilation between the two populations. In addition, these results support the robustness claim of multivariate analysis to represent phenomena that phylogenetic analyses may not be able to demonstrate, especially for massive panel data.