RESUMO
Short tandem repeat (STR) polymorphisms have been extensively used in forensic genetics analysis. Knowledge about the locus-specific mutation rates of STRs improves forensic probability calculations and interpretations of diversity data. To incorporate single-locus diversity information into autosomal STR mutation rate estimations, 13 STR loci were studied during 2007-2009 in 10,959 paternity investigation cases from Rio Grande do Sul, the southernmost state of Brazil, covering an overall number of 284,934 allelic transfers. A total of 355 mutations were identified; 348 repeats were gains or losses of one step, three were gains or losses of two steps, and four were gains or losses of not stepwise mutation. The mutation rates ranged from 4.6 × 10(-5) to 2.3 × 10(-3), and the overall mutation rate estimate was 1.2 × 10(-3). The average of the paternal mutation rate (1.8 × 10(-3)) was five times higher than the maternal rate (0.36 × 10(-3)). The observed mutational features for STRs have important consequences for forensic applications, including the definition of criteria for exclusion in paternity testing and the interpretation of DNA profiles in identification analysis.
Assuntos
Loci Gênicos , Genética Populacional , Repetições de Microssatélites , Taxa de Mutação , Brasil , Impressões Digitais de DNA , Feminino , Humanos , Masculino , Reação em Cadeia da PolimeraseRESUMO
Allele frequencies for 11 STR autosomal loci (D3S1358, vWA, D16S539, D2S1338, D8S1179, SE33, D19S433, TH01, FGA, D21S11, D18S51) were analysed in unrelated individuals undergoing paternity testing in Rio Grande do Sul State, Southern Brazil. The most polimorphic locus was SE33. The distributions of the genotypes in the evaluated loci are in Hardy-Weinberg equilibrium after Bonferroni's correction.
Assuntos
Frequência do Gene , Genética Populacional , Sequências de Repetição em Tandem , Brasil , Impressões Digitais de DNA , Humanos , Masculino , Paternidade , Reação em Cadeia da PolimeraseRESUMO
Allele frequencies for 15 short tandem repeats (STR) loci were obtained from a sample of 2038 individuals undergoing paternity testing. The population is from Rio Grande do Sul, Brazil. The loci are the most commonly used in forensic and paternity testing, being analysed by the AmpFlSTR Identifiler (Applied Biosystems) commercial kit. The most polymorphic locus was D2S1338. Mutation rates were ascertained from this population sample. All the loci analysed reached the Hardy-Weinberg equilibrium. The results of genetic distance are consistent with the European-derived origins of Rio Grande do Sul population.
