Ancestry analysis using autosomal SNPs in northern South America, reveals interpretation differences between an AIM panel and an identification panel.

Current human populations are studied to elucidate their ancestry composition and to obtain reference values for an array of genetic markers for forensic practice. This study compared the 79 ancestry informative markers (AIMs) panel with the SNPforID 52plex set used in forensic identification, using samples belonging to Continental Caribbean populations from Colombia with a high percentage of locals self-determined as Native American descendants. The results show a bias in the individual estimation made with the identification markers, which disregards the Native American ancestry component and overestimates the African ancestry component. Also, the analysis made with the Bayesian Classification Algorithm shows better likelihoods for individual assignment with AIMs than with SNPforID 52plex.

Applicability of the SNPforID 52-plex panel for human identification and ancestry evaluation in a Brazilian population sample by next-generation sequencing.

SNP analysis is of paramount importance in forensic genetics. The development of new technologies in next-generation sequencing allowed processing a large number of markers in various samples simultaneously. Although SNPs are less informative than STRs, they present lower mutation rates and perform better when using degraded samples. Some SNP systems were developed for forensic usage, such as the SNPforID 52-plex, from the SNPforID Consortium, containing 52 bi-allelic SNPs for human identification. In this paper we evaluated the informativeness of this system in a Brazilian population sample (n = 340). DNA libraries were prepared using a customized HaloPlex Target Enrichment System kit (Agilent Technologies, Inc.) and sequenced in the MiSeq Personal Sequencer platform (Illumina Inc.). The methodology presented here allowed the analysis of 51 out of 52 SNPforID markers. Allele frequencies and forensic parameters were estimated, revealing high informativeness: the combined match probability and power of exclusion were 6.48 × 10-21 and 0.9997, respectively. Population admixture analysis indicates high European contribution (more than 70%) and low Amerindian contribution (less than 10%) in our population, while individual admixture analyses were consistent with the majority of individuals presenting high European contribution. This study demonstrates that the 52-plex kit is suitable for forensic cases in a Brazilian population, presenting results comparable with those obtained using a 16 STR panel.

Autosomal SNPs study of a population sample from Southern Portugal and from a sample of immigrants from Guinea-Bissau residing in Portugal.

In recent years, autosomal single nucleotide polymorphisms (SNPs) have been comprehensively investigated in forensic research due to their usefulness in certain circumstances in complementing short tandem repeats (STRs) analysis, or even for use on their own when analysis of STRs fails. However, as with STRs, in order to properly use SNP markers in forensic casuistic we need to understand the population and forensic parameters in question. As a result of Portugal's colonial history during the time of empire, and the subsequent process of decolonization, some African individuals migrated to Portugal, giving rise to large African and African-descendent communities. One of these groups is the community originating from Guinea-Bissau, that in 2014, was enumerated to consist of more than 17,700 individuals with official residency status, more than the third major city of Guinea-Bissau. In order to study the population and forensic parameters mentioned above for the two populations important to our casuistic, a total of 142 unrelated individuals from the South of Portugal and 90 immigrants from Guinea-Bissau (equally non related and all residing in Portugal) were typed with SNaPshot™ assay for all 52 loci included in the SNPforID 52plex.