Forensic inference of biogeographical ancestry from genotype: The Genetic Ancestry Lab

Short tandem repeat (STR) profiling of DNA has become ubiquitous in forensic practice and is used to associate people, objects, and places with each other and with crimes. STRs can include or exclude a suspect or victim as the donor of biological evidence. In the absence of a matching profile, however, STRs have limited value. It is possible, then, to extract other information from the DNA that might lead forensic investigators to an offender. Examples include biogeographical ancestry (BGA) and externally visible characteristics (EVCs). These require alternative genetic markers including single nucleotide polymorphisms and microhaplotypes which can be genotyped on many different platforms including capillary electrophoresis, microarrays, and massively parallel sequencing (MPS). The Genetic Ancestry Lab (GAL) in Australia provides estimates of BGA and EVCs derived from DNA that is extracted from biological evidence and then subjected to targeted amplicon enrichment and subsequent MPS. This review will describe the process of BGA prediction employed by the GAL as well as describing alternative practices. Limitations are addressed and future directions highlighted, including resolution of genetic admixture. It is highly likely that inference of BGA will become standard forensic practice, performed simultaneously with or in addition to STR profiling, and it is hoped that this review might provide a road map. This article is categorized under: Forensic Anthropology > Ancestry Determination Forensic Science in Action/Crime Scene Investigation > From Traces to Intelligence and Evidence Forensic Biology > Ancestry Determination using DNA Methods Forensic Biology > Forensic DNA Technologies