Browsing by Author "Carvalho, Elizeu"
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- A GEP-ISFG collaborative study on the optimization of an X-STR decaplex: data on 15 Iberian and Latin American populationsPublication . Gusmão, Leonor; Sánchez-Diz, Paula; Alves, Cíntia; Gomes, Iva; Zarrabeitia, María Teresa; Abovich, Mariel; Atmetlla, Ivannia; Bobillo, Cecilia; Bravo, Luisa; Builes, Juan; Cainé, Laura; Calvo, Raquel; Carvalho, Elizeu; Carvalho, Mónica; Cicarelli, Regina; Catelli, Laura; Corach, Daniel; Espinoza, Marta; García, Óscar; Malaghini, Marcelo; Martins, Joyce; Pinheiro, Fátima; João Porto, Maria; Raimondi, Eduardo; Riancho, Jose Antonio; Rodríguez, Amelia; Rodríguez, Anayanci; Rodríguez Cardozo, Belén; Schneider, Vicente; Silva, Sandra; Tavares, Celso; Toscanini, Ulises; Vullo, Carlos; Whittle, Martin; Yurrebaso, Iñaki; Carracedo, Ángel; Amorim, AntónioIn 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.
- Microsatellites’ mutation modeling through the analysis of the Y-chromosomal transmission: Results of a GHEP-ISFG collaborative studyPublication . Antão-Sousa, Sofia; Gusmão, Leonor; Modesti, Nidia M.; Feliziani, Sofía; Faustino, Marisa; Marcucci, Valeria; Sarapura, Claudia; Ribeiro, Julyana; Carvalho, Elizeu; Pereira, Vania; Tomas, Carmen; de Pancorbo, Marian M.; Baeta, Miriam; Alghafri, Rashed; Almheiri, Reem; Builes, Juan José; Gouveia, Nair; Burgos, German; Pontes, Lurdes; Ibarra, Adriana; Silva, Cláudia Vieira da; Parveen, Rukhsana; Benitez, Marc; Amorim, Antonio; Pinto, NádiaThe Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) organized a collaborative study on mutations of Y-chromosomal short tandem repeats (Y-STRs). New data from 2225 father-son duos and data from 44 previously published reports, corresponding to 25,729 duos, were collected and analyzed. Marker-specific mutation rates were estimated for 33 Y-STRs. Although highly dependent on the analyzed marker, mutations compatible with the gain or loss of a single repeat were 23.2 times more likely than those involving a greater number of repeats. Longer alleles (relatively to the modal one) showed to be nearly twice more mutable than the shorter ones. Within the subset of longer alleles, the loss of repeats showed to be nearly twice more likely than the gain. Conversely, shorter alleles showed a symmetrical trend, with repeat gains being twofold more frequent than reductions. A positive correlation between the paternal age and the mutation rate was observed, strengthening previous findings. The results of a machine learning approach, via logistic regression analyses, allowed the establishment of algebraic formulas for estimating the probability of mutation depending on paternal age and allele length for DYS389I, DYS393 and DYS627. Algebraic formulas could also be established considering only the allele length as predictor for DYS19, DYS389I, DYS389II-I, DYS390, DYS391, DYS393, DYS437, DYS439, DYS449, DYS456, DYS458, DYS460, DYS481, DYS518, DYS533, DYS576, DYS626 and DYS627 loci. For the remaining Y-STRs, a lack of statistical significance was observed, probably as a consequence of the small effective size of the subsets available, a common difficulty in the modeling of rare events as is the case of mutations. The amount of data used in the different analyses varied widely, depending on how the data were reported in the publications analyzed. This shows a regrettable waste of produced data, due to inadequate communication of the results, supporting an urgent need of publication guidelines for mutation studies.