Compilação e análise crítica sobre a utilização do DNA mitocondrial em casos forenses na população brasileira em comparação com outros países da América Latina e do mundo
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Data
2017-02-14
Autores
Hyppolito, Caroline da Silva [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O DNA mitocondrial é uma molécula circular, dupla fita, que se encontra na mitocôndria, uma organela responsável pela respiração e produção de energia da célula. Este DNA é herdado exclusivamente por via materna e possui polimorfismos que permitem diferenciar indivíduos, auxiliando nas investigações forenses e corroborando com outros exames de identificação humana. Devido à possibilidade de compatibilidade deste DNA entre indivíduos não relacionados por via materna, é necessário estimar as frequências haplotípicas utilizando bancos de dados populacionais. Com a finalidade de se compilar e avaliar a utilização do DNA mitocondrial no Brasil realizou-se um estudo sobre os haplótipos depositados no banco de dados do European DNA Profiling Mitochondrial DNA Population Database (EMPOP) e acessando artigos científicos sobre dados de populações brasileiras, observando os países participantes e seus respectivos dados depositados. Na avaliação dos dados do EMPOP, a América do Norte foi o continente com maior número de haplótipos depositados no banco, principalmente pela participação dos Estados Unidos. A América do Sul contém 3172 haplótipos, sendo 782 desse total correspondentes ao Brasil. Esses números parecem insuficientes para representar a população grande e miscigenada do país. Na literatura, encontrou-se um total de 2367 haplótipos, os quais foram organizados por haplogrupos e as regiões brasileiras correspondentes: Sudeste e Nordeste apresentaram-se similares, com predomínio de ancestralidade africana (44%), enquanto o Sul apresentou uma origem predominantemente europeia (68,4%) e a região Norte de nativo-americanos (58,8%). As regiões Centro-Oeste, Norte e Nordeste carecem de mais estudos, pois os dados referentes a essas regiões são muito escassos. A população brasileira demonstrou alta diversidade genética que reflete sua miscigenação, sendo que na avaliação da distância genética, as populações do Sul do Brasil ficaram mais próximas da população portuguesa, enquanto que as do Norte se aproximaram da africana. Os dados da literatura permitem concluir que, a matrilinhagem do Brasil é predominantemente de origem africana (37%), seguida da europeia (35%) e de nativo-americanos (28%). Além disso, a diferença entre as quantidades de dados brasileiros no banco e na literatura indica a dificuldade dos laboratórios em atender aos controles de qualidade exigidos para deposição de amostras no EMPOP. Para avaliação da complexidade da metodologia de análise do DNA mitocondrial, cinco amostras de referência foram sequenciadas para as regiões HV1, HV2 e HV3 e os resultados confirmaram as sequências informadas previamente. Isto permitiu verificar que, com a utilização de uma metodologia adequadamente padronizada para análise de DNA mitocondrial foi possível obter resultados satisfatórios, mesmo que o operador tenha pouca experiência na técnica. Assim, a utilização correta de uma metodologia padronizada permitirá atender aos controles de qualidade exigidos pelo EMPOP, ainda que a técnica apresente várias etapas críticas para a obtenção do sequenciamento de qualidade.
Mitochondrial DNA is a circular and double-stranded molecule found in the mitochondria, an organelle responsible for breathing and energy production of the cell. This DNA is exclusively inherited through maternal and has polymorphisms that allow differentiating individuals, it assists in forensic investigations and corroborates with other tests of human identification. Due to the possibility of compatibility of this DNA between unrelated individuals, it is necessary to estimate the haplotype frequencies through population databases. In order to compile and evaluate the use of mitochondrial DNA in Brazil, a study was carried out about the haplotypes deposited in the European DNA Profiling Mitochondrial DNA Population Database (EMPOP), and acessing scientific articles with data from Brazilian populations, verifying participating countries and their respective deposited data. In the evaluation of EMPOP data, North America was the continent with the highest number of data deposited in the bank, mainly by the participation of the United States. South America contains 3172 haplotypes, 782 of which correspond to Brazil. These numbers seem insufficient to represent the large and mixed population of this country. In the literature, a total of 2367 haplotypes were found, which were organized by haplogroups and the corresponding Brazilian regions: the Southeast and Northeast were similar, with predominance of African ancestry (44%), while the South had a predominantly European origin (68.4%) and the North of Native Americans (58.8%). The Center-West, North and Northeast regions need further studies,therefore, the data for these regions are very scarce. Brazilian population have shown high genetic diversity that reflects your miscegenation, and in the genetic distance evaluation, the populations of the South of Brazil are genetically closer to the Portuguese population, while those from the North are closer to the African ones. According to literature data, it is possible to conclude that Brazil's matriarchy is predominantly African (37%), followed by European (35%) and Native American (28%). In addition, the difference between the Brazilian data in the database and the literature indicates the difficulty of the laboratories to meet the quality controls required for EMPOP deposition. To evaluate the complexity of the mitochondrial DNA analysis methodology, five reference samples had the HV1, HV2 and HV3 regions sequenced and the results confirmed the previously reported sequences. This allows to verify that with the use of a adequately standardized methodology for mitochondrial DNA analysis it is possible to obtain satisfactory results, even the operator having little experience in the technique. Therefore, the correct use of a standardized methodology, allows to meet the quality controls required by EMPOP, even the technique presents several critical steps to obtain quality sequencing.
Mitochondrial DNA is a circular and double-stranded molecule found in the mitochondria, an organelle responsible for breathing and energy production of the cell. This DNA is exclusively inherited through maternal and has polymorphisms that allow differentiating individuals, it assists in forensic investigations and corroborates with other tests of human identification. Due to the possibility of compatibility of this DNA between unrelated individuals, it is necessary to estimate the haplotype frequencies through population databases. In order to compile and evaluate the use of mitochondrial DNA in Brazil, a study was carried out about the haplotypes deposited in the European DNA Profiling Mitochondrial DNA Population Database (EMPOP), and acessing scientific articles with data from Brazilian populations, verifying participating countries and their respective deposited data. In the evaluation of EMPOP data, North America was the continent with the highest number of data deposited in the bank, mainly by the participation of the United States. South America contains 3172 haplotypes, 782 of which correspond to Brazil. These numbers seem insufficient to represent the large and mixed population of this country. In the literature, a total of 2367 haplotypes were found, which were organized by haplogroups and the corresponding Brazilian regions: the Southeast and Northeast were similar, with predominance of African ancestry (44%), while the South had a predominantly European origin (68.4%) and the North of Native Americans (58.8%). The Center-West, North and Northeast regions need further studies,therefore, the data for these regions are very scarce. Brazilian population have shown high genetic diversity that reflects your miscegenation, and in the genetic distance evaluation, the populations of the South of Brazil are genetically closer to the Portuguese population, while those from the North are closer to the African ones. According to literature data, it is possible to conclude that Brazil's matriarchy is predominantly African (37%), followed by European (35%) and Native American (28%). In addition, the difference between the Brazilian data in the database and the literature indicates the difficulty of the laboratories to meet the quality controls required for EMPOP deposition. To evaluate the complexity of the mitochondrial DNA analysis methodology, five reference samples had the HV1, HV2 and HV3 regions sequenced and the results confirmed the previously reported sequences. This allows to verify that with the use of a adequately standardized methodology for mitochondrial DNA analysis it is possible to obtain satisfactory results, even the operator having little experience in the technique. Therefore, the correct use of a standardized methodology, allows to meet the quality controls required by EMPOP, even the technique presents several critical steps to obtain quality sequencing.
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DNA mitocondrial - Brasil, Banco de dados, EMPOP