Genetic frequency of 17 STR markers in a smaple of students from Escola Paulista de Medicina, Universidade Federal de São Paulo

• Grant number: 11/09806-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2011
• End date: July 31, 2013
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Edna Sadayo Miazato Iwamura
• Grantee: Marco Aurélio de Oliveira
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

The microsatellite or Short Tandem Repeats (STRs) markers are characterized by high levels of heterozygosity, uniform dispersion, high reproducibility, codominance and possibility of for genotyping using sensitive methods. Because of these characteristics, these markers have been widely used in population genetics, evolutionary studies and forensic analysis. In Brazil, we have several tables of population frequency, but the need for the introduction of new STR markers has been demonstrated in many situations.In this study, after informed consent, blood samples will be collected on FTA filter paper from 400 voulunteers individuals, not related in age from 18 to 26 years, male and female students from the School of Medicine and Biomedicine, EPM / UNIFESP. After DNA extraction, will be used the genotyping system PowerPlex that allows co-amplification and fluorescence detection of 17 loci (16 STR and amelogenin), 8 CODIS (Combined DNA Index System) and other 8 new loci. The system includes D18S51, D21S11, TH01, D3S1358, Amelogenin, D16S539, D2S1338, D1S1656, D10S1248, FGA, D8S1179, vWA, D22S1045, SE33, D19S433, D12S391 and D2S441. The kits have a higher tolerance to common inhibitors and increased sensitivity to obtain full profiles from DNA of low level and are robust enough for genotyping degraded DNA samples through the use of miniSTR loci It is distributed among 17 loci mini, midi and mega STR. The Powerplex ESX17 ® system is compatible with ABI PRISM ® 310, 3100 and 3100-Avant Genetic Analyzers and Applied Biosystems 3130xl Genetic Analyzers and 3130.In criminal cases, where the sample size is small and DNA highly degraded, it is interesting that there is an increasing number of DNA regions analyzed, making necessary the use, beyond the set of STRs commonly analyzed, other genetic markers. This requires knowledge of the allele frequencies of STRs in the specific population. The new polymorphic regions to be analyzed in the population of São Paulo are: D2S441, D10S1248, D22S1045, D1S1656 and D12S391.These data may be used for statistical calculations in more complex civil cases in private or state laboratories for investigating the genetic kinship or identity by DNA, for the State of Sao Paulo, as IMESC (Institute of Social Medicine and Criminology). Moreover, this study is of extreme importance in cases of degraded samples, and certainly will be used in the laboratories of molecular biology of the Institute of Criminology of São Paulo and other States of Brazil.