Adriana Castillo

Genetic profile characterization and segregation analysis of 10 X-STRs in a sample from Santander, Colombia

Ten X-chromosome short tandem repeats (X-STRs: DXS8378, DXS7132, DXS9898, DXS6809, DXS6789, DXS101, GATA172D05, HPRTB, DXS8377, and DXS7423) were analyzed in a sample of unrelated individuals (108 males and 110 females) from the Santander Department in Colombia. In this sample, gene diversities varied between 63.56%, for DXS8378, and 91.41%, for DXS8377. For this set of 10 X-STRs, a high discrimination power was obtained for both male (1 in 3 × 106) and female (1 in 9 × 1010) samples and a high mean exclusion chance in father/daughter duos (99.993%) and in father/mother/daughter trios (99.9999%), demonstrating the usefulness of this set of markers in forensic and kinship analysis. Hardy–Weinberg equilibrium was tested in the female sample and no significant deviations were found. Pairwise analysis showed significant differences in the comparison with samples from Spain, Peru, and Argentina and with African American and Hispanic samples from New York. This same set of X-STRs was also typed in 51 mother/father/daughter trios, 43 mother/son duos, and in a single father/daughter pair. In total, four mutations were observed; one at DXS7132 and at DXS6809, and two at DXS8377. Two mutations were paternal and one maternal; and to a fourth mutation, it was not possible to define its origin.

Evaluating the X Chromosome-Specific Diversity of Colombian Populations Using Insertion/Deletion Polymorphisms

The European and African contribution to the pre-existing Native American background has influenced the complex genetic pool of Colombia. Because colonisation was not homogeneous in this country, current populations are, therefore, expected to have different proportions of Native American, European and African ancestral contributions. The aim of this work was to examine 11 urban admixed populations and a Native American group, called Pastos, for 32 X chromosome indel markers to expand the current knowledge concerning the genetic background of Colombia. The results revealed a highly diverse genetic background comprising all admixed populations, harbouring important X chromosome contributions from all continental source populations. In addition, Colombia is genetically sub-structured, with different proportions of European and African influxes depending on the regions. The samples from the North Pacific and Caribbean coasts have a high African ancestry, showing the highest levels of diversity. The sample from the South Andean region showed the lowest diversity and significantly higher proportion of Native American ancestry than the other samples from the North Pacific and Caribbean coasts, Central-West and Central-East Andean regions, and the Orinoquian region. The results of admixture analysis using X-chromosomal markers suggest that the high proportion of African ancestry in the North Pacific coast was primarily male driven. These men have joined to females with higher Native American and European ancestry (likely resulting from a classic colonial asymmetric mating type: European male x Amerindian female). This high proportion of male-mediated African contributions is atypical of colonial settings, suggesting that the admixture occurred during a period when African people were no longer enslaved. In the remaining regions, the African contribution was primarily female-mediated, whereas the European counterpart was primarily male driven and the Native American ancestry contribution was not gender biased.

Population genetic data for 13 STR loci in a northeast Colombian (department of Santander) population

Abstract Before a new marker system can be introduced into forensic casework, a database for the relevant population must be established for statistical evaluation of the evidence. Therefore, this report presents allele frequency data in a northeast Colombian (department of Santander) population sample (n=103–399) for the loci TH01, TPOX, CSF1PO, D3S1358, FGA, VWA, D5S818, D13S317, D7S820, D8S1179, D21S11, D18S51 and D16S539. The combined power of exclusion is estimated as 99.9988% and the combined power of discrimination is >99.99999%. These 13 STR systems have been shown to be a useful tool for personal identification. The allele frequency data can be used for deriving estimates of multiple locus profile frequencies for identity testing purposes using the product rule.

Allele frequencies for the AmpFlSTR profiler loci in a Colombian population (Department of Boyaca).

Whole blood samples were obtained in the genetics laboratory of the UIS (Universidad Industrial of Santander) and Boyaca Regional ICBF (Instituto Colombiano de Bienestar Familiar) from 183 unrelated Colombian donors (Department of Boyaca). Genomic DNA was extracted using the salting out procedure. PCR amplification was performed using the AmpFlSTR Profiler amplification kit (PE-Biosystems, Foster City, CA) following manufacturers instructions. The amplified products were separated and detected using the ABI 310 DNA sequencer (PE-Biosystems, Foster City, CA). Alleles were classified according to the recommendations of the ISFH (1). Statistical analysis was performed as previously reported (2). The complete data set is available to any interested researcher upon request from the corresponding author, Oscar Garcia, Ph.D.

Genetic Variation for Penta D and Penta E in a Northeast Colombian Population (Department of Santander)

POPULATION: Department of Santander, Colombia (n=104).

A GHEP-ISFG collaborative study on the genetic variation of 38 autosomal indels for human identification in different continental populations

A collaborative effort was carried out by the Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) to promote knowledge exchange between associate laboratories interested in the implementation of indel-based methodologies and build allele frequency databases of 38 indels for forensic applications. These databases include populations from different countries that are relevant for identification and kinship investigations undertaken by the participating laboratories. Before compiling population data, participants were asked to type the 38 indels in blind samples from annual GHEP-ISFG proficiency tests, using an amplification protocol previously described. Only laboratories that reported correct results contributed with population data to this study. A total of 5839 samples were genotyped from 45 different populations from Africa, America, East Asia, Europe and Middle East. Population differentiation analysis showed significant differences between most populations studied from Africa and America, as well as between two Asian populations from China and East Timor. Low FST values were detected among most European populations. Overall diversities and parameters of forensic efficiency were high in populations from all continents.

Polimorfismo S19W (Ser19Ter) de la APOA5 y su relación con la hipertrigliceridemia en una población de Colombia

Introduccion: Las enfermedades cardiovasculares (ECV) son responsables del 29,69% de las muertes en Colombia. Se ha encontrado la hipertrigliceridemia, en diversos estudios como factor de riesgo independiente para la ECV. El polimorfismo S19W (Ser19Ter) de la ApoA5 se ha asociado en algunas poblaciones con la hipertrigliceridemia. Sin embargo, en Colombia esto ha sido poco estudiado. Objetivo: Estimar la asociacion entre el polimorfismo S19W y la hipertrigliceridemia en poblacion colombiana. Metodologia: Estudio tipo Corte Transversal, con 400 individuos provenientes de Bucaramanga, Colombia. Se cuantifico los TAG y se genotipificaron mediante la tecnica de SNaPshot y mini secuenciacion. Los resultados fueron analizados utilizando el software de analisis genetico Arlequin 3.5.1.2. Resultados: El polimorfismo S19W (Ser19Ter) mostro tres perfiles, CC, GG y CG. El polimorfismo S19W se caracterizo tanto en afectados como en no afectados, mostrando que no existen diferencias significativas en esta distribucion cuando se comparan los dos grupos. Discusion: Diversos mecanismos se han propuesto para sustentar la hipertrigliceridemia como un factor de riesgo para ECV, entre los que se cuenta la APOA5. El estudio comprobo que la poblacion estudiada se encuentra en equilibrio de Hardy Weinberg y al genotipo CC como el mas frecuente. Los genotipos GG y el GC presentaron valores significativos en el grupo de sujetos afectados, (p<0,01 y p=0,03; respectivamente). Se demostro la existencia de una estrecha relacion entre el polimorfismo Ser19Trp y la hipertrigliceridemia (p<0,01). Conclusion: Se pudo demostrar la existencia de una relacion entre el polimorfismo Ser19Trp de la Apo A5 con los niveles elevados de TAG (p<0,01).