Use of Next‐Generation Sequencing in Forensic Genetics

Abstract

The main purpose of forensic science institutions is to provide scientifically based investigations to the judicial system and assist society as a whole with objective analyses of evidence. Ten years ago, the invention of clonal amplification by emulsion PCR or bridge PCR inspired a technical revolution in DNA sequencing commonly known as next‐generation sequencing (NGS). New methods and platforms were invented, all with the same purpose of sequencing massive numbers of DNA molecules simultaneously. These methods are of obvious interest to forensic genetic practitioners, who are frequently faced with the challenge of genotyping limited and degraded DNA material extracted from irreplaceable trace samples. NGS may be superior to the existing techniques and offers new exiting possibilities to the end users of forensic investigations. Key Concepts Next‐generation sequencing (NGS) is based on simultaneous clonal amplification of millions of individual DNA molecules and parallel sequencing of the generated products. Fragment length analyses of PCR‐amplified short tandem repeats (STRs) have been the preferred method for human identification in forensic genetic case work for more than two decades. The multiplexing capability of PCR‐NGS and sequencing capacity of NGS platforms make it possible to type different types of markers (STRs, SNPs and INDELs) in one assay, which increases the available information, saves time and reduces the overall cost of the investigation. Human identification and forensic phenotyping may be accomplished simultaneously by typing human identification and phenotypical markers in one PCR‐NGS assay. Detailed sequence information of STRs increases the statistical weight of the DNA evidence and may aid mixture interpretation. Genome or transcriptome sequencing of samples from deceased makes it possible to combine forensic pathology with medical genetics and forensic toxicology with pharmacogenetics.

Análise de marcadores forenses (STRs e SNPs) rotineiramente empregados na identificação humana utilizando sequenciamento de nova geração

“…A utilização de NGS em investigações forenses surge trazendo numerosos benefícios com diferentes possibilidades de análise. Com início das aplicações voltadas principalmente para identificação humana e determinação de traços fenotípicos, as plataformas de NGS tem a possibilidade de análises extremamente amplas, como análise de STRs, SNPs, INDELs genomas mitocondriais, cromossomos Y, ancestralidade, análises microbiológicas, análises de DNA de plantas e animais, análises epigenéticas e de diferentes tipos de RNAs, e outras possibilidades (Børsting e Morling 2017;Butler 2015;Hunter 2018;Yang et al 2014).…”

“…Algumas iniciativas já aparecem em destaque no campo acadêmico como os programas STRait Razor ) e toaSTR (Ganschow et al 2017). Plataformas mais compactas de bancadas vem sendo desenvolvidas e podem ser uma alternativa promissora para área principalmente por sua flexibilidade (Borsting e Morling 2015;Børsting e Morling 2017;Yang et al 2014).…”