RESUMO
Neutrality investigations of markers with forensic use are important to see if a phenotypic trait is being expressed in relation to the alleles of the marker. MiniSTR marker D22S1045 (locus 22q12.3) is localized near the breakpoint region of the EWS gene (22q12.2), which leads to the development of Ewing's Sarcoma. Analyzing allele frequencies and linkage disequilibrium in Ewing's sarcoma patients and non-affected populations, we found that the marker mD22S1045 was neutral when related to Ewing's Sarcoma.
Assuntos
Cromossomos Humanos 21-22 e Y/genética , Genética Forense/métodos , Desequilíbrio de Ligação/genética , Sarcoma de Ewing/genética , Alelos , Estudos de Casos e Controles , Impressões Digitais de DNA/métodos , Marcadores Genéticos , Humanos , Repetições de Microssatélites/genética , FenótipoRESUMO
A task-force to resolve 26 pending forensic caseworks was carried out. We tested four different protocols to extract DNA from molar and pre-molar teeth from 26 cadavers with post-mortem intervals from 2 months to 12 years. We compared the amount of DNA and DNA profiles with the time elapsed between death and laboratory procedures. Molar or pre-molar teeth were removed from the corpses, cleaned, and DNA was extracted using 2 or 12h of incubation on lysis buffer and filtered using concentration column or precipitated with isopropanol. DNA profiles were obtained using PowerPlex16™ System PCR Amplification Kit, AmpFlSTR(®) Yfiler™ and/or mtDNA sequencing. Complete DNA profiles comparison and statistical evaluation allowed unambiguous identification of the 26 victims. No significant differences were observed in the amount of DNA obtained with the distinct incubation times. The use of concentration column resulted in an increased amount of DNA when compared to isopropanol. However, the lower concentration of DNA obtained with isopropanol seemed to have been compensated by the higher purity. No significant differences in the number of amplified loci were found. A non-significant tendency was found between the amount of total DNA recovered and the time elapsed between death and laboratory procedures. The increase of post-mortem time did not interfere in the analysed autosomal loci. In conclusion, molar and pre-molar teeth were shown to be good candidates to obtain satisfactory DNA profiles, suggesting the high potential of tooth samples as source for DNA typing independently of the decomposed corpse's time or laboratory procedures.
Assuntos
Cadáver , Impressões Digitais de DNA/métodos , DNA/isolamento & purificação , Odontologia Legal/métodos , Dente Molar/química , Análise de Variância , Feminino , Loci Gênicos , Humanos , Masculino , Mudanças Depois da MorteRESUMO
A sample of 255 Brazilian males from Rio Grande do Sul (RS), the Brazilian southernmost state, was typed for 17 Y-STR loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, YGATA_H4.1 and DYS385ab). A total of 247 haplotypes were identified, of which 239 were unique and eight were found in two individuals each. The haplotype diversity (99.98%) and discrimination capacity (96.86%) were calculated. Pairwise haplotype distances showed that the RS population is not significantly different from Brazil, Rio de Janeiro, and Argentina, is different from São Paulo, Italy, and North Portugal, and is very distant from Spain, the Amazon region, Germany, and South Amerindians. When the RS data was separated in the seven geopolitical regions, some pairs of regions were significantly different; however no region was different from the whole Brazilian sample.
Assuntos
Cromossomos Humanos Y , Genética Populacional , Sequências de Repetição em Tandem , Brasil , Impressões Digitais de DNA , Frequência do Gene , Haplótipos , Humanos , Masculino , Reação em Cadeia da PolimeraseRESUMO
A sample of 203 Brazilian males from Rio Grande do Sul (RS), the Brazilian southernmost state, was typed for 11 Y-STR markers (DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438, and DYS439). We also typed 42 individuals from two South Amerindian tribes (Kaingang and Guarani) to use the data as parental Amerindian contribution to our analyses. Gene and haplotypic diversities were estimated, with the South Amerindian samples showing smaller values for these parameters than Brazilians. To obtain a more comprehensive picture of the genetic structure of the Brazilian population as a whole, the Y-STR data from the RS sample was compared with those already published. No genetic substructuring was observed in the comparisons performed. Multidimensional scaling confirmed the proposed European source of most Y-chromosome Brazilian patrilineages.
Assuntos
Cromossomos Humanos Y/genética , Genética Populacional/métodos , Índios Sul-Americanos/estatística & dados numéricos , Repetições de Microssatélites/genética , Alelos , Brasil , Feminino , Frequência do Gene , Variação Genética , Genômica , Haplótipos , Humanos , Masculino , América do Sul , Sequências de Repetição em TandemRESUMO
Allele frequencies for 09 STR autosomal loci (D3S1358, D5S818, D7S820, D8S1179, D13S317, D18S51, D21S11, FGA and VWA) included in the AmpFlSTR Profiler Plus were obtained from a sample of unrelated individuals from Rio Grande do Sul (southern Brazil).
