Genetic study of 15 autosomal STR loci in the population from Araraquara region (São Paulo State Brazil)

Abstract

Introduction: Genetic characterization of markers is needed to evaluate the polymorphism in different populations and to establish reference databases useful in forensic applications and anthropological studies. Thus, the aim of the current study was to determine the allele frequencies and some statistical parameters of forensic and paternity interest for 15 STR loci included in PowerPlex® 16 System kit (D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX and FGA) in the population from Araraquara region, São Paulo State, Brazil. Methods: Blood samples from 403 unrelated individuals living in Araraquara region were collected on FTA cards and genomic DNA was extracted using the FTA method 16 Systems kit (Whatman). The amplification was performed using PowerPlex (Promega), following the manufacturer's recommendations. Separation and detection were carried out by ABI377 automated sequencer (Applied Biosystems) and genotyping was performed by comparison with the Ladder included in the kit using GeneScan 2.1 software (Applied Biosystems). The allele frequencies and exact test of the Hardy-Weinberg equilibrium were calculated using the ARLEQUIN software v 3.1. Statistical parameters of forensic and paternity interest (Power of Discrimination, Matching Probability, Polymorphism Information Content, Power of Exclusion and Typical Paternity Index) were calculated using PowerStats software v1.2 (Promega).

Results and Discussion: For a significance level of 0.0033 (after Bonferroni correction) no deviations from Hardy-Weinberg equilibrium were observed for any of the analyzed loci. Power of discrimination values were higher than 0.86 and the polymorphic information content values ranged from 0.6450 for TPOX to 0.8863 for Penta E. Combined power of exclusion for the 15 tested STR loci was 0.999999785, respectively.

Conclusion: The 15 loci offer a highly discriminating system for paternity and forensic purpose of individuals in population from Araraq! uara reg ion. This work was supported by PADC-FCFAr-UNESP, FUNDUNESP, CNPq.