Study of allelic frequency of five X-Chromosome?s loci STR on Sao Paulo State people and its role in human identification / Estudo de freqüência alélica de cinco loci STR do cromossomo X na população do Estado de São Paulo e sua contribuição na identificação humana

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The forensic identification through DNA analysis is, frequently, done by the study of DNA?s polymorphic regions, such as STR, short tandem repeats. In order to use these markers in human identification, it?s necessary to know the allelic distribution in the population in wich the person belongs. This research aimed to settle the allelic frequencies of five X-chromosome?s STR (DXS6854, DXS7424, DXS101, DXS6808 e DXS7132) and analysis the contribution of these markers, through statistical parameters, in forensic activities and paternity tests. For this, samples of oral rub were collected by oral swab, being deposited on collect card, and/or blood by digital punction, deposited on collect card, with 243 research subject, being not related, living at Sao Paulo State, Brazil. The DNA extraction was performed using Kit DNA IQ® (Promega), according to manufacturer rules and, at PCR, was used a multiplex developed by BIOCOD (Belo Horizonte, Minas Gerais State), being the loci typifying obtained by eletrophoretical procedure, on polyacrilamid gel, using AlfExpress® (Amersham Biosciences). The results were statistically analyzed by PowerStats ver. 12 (Promega®) and Arlequin ver. 3.1 programs. The principal results showed: the great allele variability in this population sample to the selected STRs; that Power of Discrimination in women varied from 0.658 (DXS6808) to 0.975 (DXS101), as well as in men between 0.451 (DXS6808) and 0.881 (DXS101); the mean exclusion chance were calculated at two conditions, pair father/daughter (MECD) and trios involving daughters (MECT), being the best results performed by DXS101; and verify that haplotipical diversity (in men samples) was 0.9993, showing a Chance of Coincidence under 0.0007. In this way, it?s possible to conclude that, with exception of DXS6808, the other STRs loci studied can be used at forensic practice, using for statistical math in human identification and kinship testing.

ASSUNTO(S)

identificação humana forensic dentistry cromossomo x dna human identification dna x-chromosome odontologia legal

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