A GEP-ISFG collaborative study on the optimization of an X-STR decaplex: data on 15 Iberian and Latin American populations.

In a collaborative work carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG), a polymerase chain reaction multiplex was optimized in order to type ten X-chromosome short tandem repeats (STRs) in a single reaction, including: DXS8378, DXS9902, DXS7132, DXS9898, DXS6809, DXS6789, DXS7133, GATA172D05, GATA31E08, and DXS7423. Using this X-decaplex, each 17 of the participating laboratories typed a population sample of approximately 200 unrelated individuals (100 males and 100 females). In this work, we report the allele frequencies for the ten X-STRs in 15 samples from Argentina (Buenos Aires, Córdoba, Río Negro, Entre Ríos, and Misiones), Brazil (São Paulo, Rio de Janeiro, Paraná, and Mato Grosso do Sul), Colombia (Antioquia), Costa Rica, Portugal (Northern and Central regions), and Spain (Galicia and Cantabria). Gene diversities were calculated for the ten markers in each population and all values were above 56%. The average diversity per locus varied between 66%, for DXS7133, and 82%, for DXS6809. For this set of STRs, a high discrimination power was obtained in all populations, both in males (> or =1 in 5 x 10(5)) and females (> or =1 in 3 x 10(9)), as well as high mean exclusion chance in father/daughter duos (> or =99.953%) and in father/mother/daughter trios (> or =99.999%). Genetic distance analysis showed no significant differences between northern and central Portugal or between the two Spanish samples from Galicia and Cantabria. Inside Brazil, significant differences were found between Rio de Janeiro and the other three populations, as well as between São Paulo and Paraná. For the five Argentinean samples, significant distances were only observed when comparing Misiones with Entre Ríos and with Río Negro, the only two samples that do not differ significantly from Costa Rica. Antioquia differed from all other samples, except the one from Río Negro.

A Basque Country autochthonous population study of 11 Y-chromosome STR loci.

Haplotype, allele frequencies and population data of 11 Y-chromosome STR loci DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS438 and DYS439 were determined from a sample of 168 unrelated autochthonous male individuals from the Basque Country. The eight surnames and birth places of the grandparents of all analyzed individuals were of Basque origin. A total of 89 haplotypes were identified by the 11 Y-STR loci. The haplotype diversity (97.49%) and discrimination capacity (52.98%) were calculated. Comparisons were made with previously published haplotype data on other Iberian population samples and significant differences were found.

The interplay between natural selection and susceptibility to melanoma on allele 374F of SLC45A2 gene in a South European population.

We aimed to study the selective pressures interacting on SLC45A2 to investigate the interplay between selection and susceptibility to disease. Thus, we enrolled 500 volunteers from a geographically limited population (Basques from the North of Spain) and by resequencing the whole coding region and intron 5 of the 34 most and the 34 least pigmented individuals according to the reflectance distribution, we observed that the polymorphism Leu374Phe (L374F, rs16891982) was statistically associated with skin color variability within this sample. In particular, allele 374F was significantly more frequent among the individuals with lighter skin. Further genotyping an independent set of 558 individuals of a geographically wider population with known ancestry in the Spanish population also revealed that the frequency of L374F was significantly correlated with the incident UV radiation intensity. Selection tests suggest that allele 374F is being positively selected in South Europeans, thus indicating that depigmentation is an adaptive process. Interestingly, by genotyping 119 melanoma samples, we show that this variant is also associated with an increased susceptibility to melanoma in our populations. The ultimate driving force for this adaptation is unknown, but it is compatible with the vitamin D hypothesis. This shows that molecular evolution analysis can be used as a useful technology to predict phenotypic and biomedical consequences in humans.

Population genetic data of 30 autosomal indels in Central Spain and the Basque Country populations.

Samples from 71 unrelated Central Spain individuals and 60 Basque Country autochthonous individuals were typed with the Investigator DIPplex kit (30 biallelic autosomal mini-indels and amelogenin) and their allele frequencies were determined. Results demonstrated the assumption of independence within and between the loci analyzed. Different partially silent alleles were observed for the locus HLD97 (rs17238892) produced by a neighboring SNP (A/G), located 61 bp downstream from the main indel site as shown by sequencing analysis.

Population data for 12 Y-chromosome STR loci in a sample from El Salvador.

Haplotype, allele frequencies and population data of 12 Y-chromosome STR loci DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439 were determined from a sample of 150 unrelated male individuals from El Salvador, Central America. A total of 131 haplotypes were identified by the 12 Y-STR loci of which 118 were unique. The haplotype diversity (99.08%) and the proportion of different haplotypes (87.33%) were estimated. R(ST) genetic distances were calculated between El Salvador and other populations from Southern and Central America, Europe and Africa. The highest R(ST) genetic distances were found when comparing El Salvador with African populations (0.334

Population data for 12 Y-chromosome STR loci in a sample from Honduras.

Haplotype, allele frequencies and population data of 12 Y-chromosome STR loci DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439 were determined from a sample of 128 unrelated male individuals from Honduras, Central America. A total of 112 haplotypes were identified by the 12 Y-STR loci of which 98 were unique. The haplotype diversity (98.99%) and the proportion of different haplotypes (87.50%) were estimated. Genetic distances were calculated between Honduras and other populations from Southern and Central America, Europe and Africa. The analysis of a Multi Dimensional Scaling (MDS) plot, based on pairwise R(ST) genetic distances, allowed to conclude that Honduras is highly differentiated from the African samples (0.343< or =R(ST)< or =0.620; P=0.000) and from a Native American sample from Argentina, Tobas (R(ST)=0.210, P=0.000). Honduras showed a lower genetic distance to the European cluster (composed by European and South American general population samples from Brazil, Argentina, Colombia and Venezuela) than to the Central American cluster (Mexico and El Salvador).

Population genetic data for 15 STR loci (Identifiler kit) in Bolivia.

Allele frequencies for 15 STR autosomal loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818 and FGA) were obtained from a sample of 200 unrelated individuals from Bolivia, South America.

Population and segregation data on 17 Y-STRs: results of a GEP-ISFG collaborative study.

A collaborative work was carried out by the Spanish and Portuguese International Society for Forensic Genetics Working Group in order to extend the existing data on Y-short tandem repeat (STR) mutations at the 17 Y chromosome STR loci included in the AmpFlSTR YFiler kit (Applied Biosystems): DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, and GATA H4.1. In a sample of 701 father/son pairs, 26 mutations were observed among 11,917 allele transfers across the 17 loci. After summing previously reported mutation data with our sample, mutation rates varied between 4.25 x 10(-4) (95% CI 0.05 x 10(-3)-1.53 x 10(-3)) at DYS438 and 6.36 x 10(-3) (95% CI 2.75 x 10(-3)-12.49 x 10(-3)) at DYS458. All mutations were single step, and mutations in the same father/son pair were found twice.

Identificación de sospechosos a través de búsquedas familiares en la base de datos de ADN de interés criminal. Implicaciones sociales, éticas y científicas / Suspects identification through 'familial searching' in DNA databases of criminal interest. Social, ethical and scientific implications

El uso de la tecnología del ADN ha revolucionado la ciencia forense en los últimos años, convirtiéndose en una herramienta de incalculable valor en los procesos de investigación e identificación forense. Además, la creación de bases de datos de perfiles genéticos de ADN ha permitido relacionar de manera eficiente personas y escenas del delito. La búsqueda familiar es una estrategia importante que permite establecer relaciones familiares entre el perfil genético hallado en la escena del delito, y objeto de la investigación, y eventuales familiares que pudieran encontrarse en dicha base de datos. Esta identificación de potenciales familiares puede permitir la identificación de la persona desconocida y la resolución del hecho delictivo. Esta estrategia de investigación cuenta con impulsores y detractores en relación con su utilización en el ámbito legal, social, ético y científico. El presente artículo revisa todos estos aspectos y aporta una visión general de la situación actual (AU)

In recent years, DNA technology has revolutionised forensic science, becoming an invaluable tool in the investigation and forensic identification processes. Moreover, the creation of DNA databases has allowed to efficiently link people and crime scenes. Familial searching is an important strategy for establishing family relationships between the genetic profile at the centre of the investigation, found at the crime scene, and any family members who might be in the database. This identification of potential relatives can lead to identification of the unknown person and the crime being solved. In the legal, social, ethical and scientific fields, this investigation strategy has both promoters and detractors regarding the effectiveness of its use. This article aims to review all these aspects and provide an overview of the current situation (AU)