Development and validation of the EUROFORGEN NAME (North African and Middle Eastern) ancestry panel.

Inference of biogeographic origin is an important factor in clinical, population and forensic genetics. The information provided by AIMs (Ancestry Informative Markers) can allow the differentiation of major continental population groups, and several AIM panels have been developed for this purpose. However, from these major population groups, Eurasia covers a wide area between two continents that is difficult to differentiate genetically. These populations display a gradual genetic cline from West Europe to South Asia in terms of allele frequency distribution. Although differences have been reported between Europe and South Asia, Middle East populations continue to be a target of further investigations due to the lack of genetic variability, therefore hampering their genetic differentiation from neighboring populations. In the present study, a custom-built ancestry panel was developed to analyze North African and Middle Eastern populations, designated the 'NAME' panel. The NAME panel contains 111 SNPs that have patterns of allele frequency differentiation that can distinguish individuals originating in North Africa and the Middle East when combined with a previous set of 126 Global AIM-SNPs.

Inference of biogeographical ancestry across central regions of Eurasia.

The inference of biogeographical ancestry (BGA) can provide useful information for forensic investigators when there are no suspects to be compared with DNA collected at the crime scene or when no DNA database matches exist. Although public databases are increasing in size and population scope, there is a lack of information regarding genetic variation in Eurasian populations, especially in central regions such as the Middle East. Inhabitants of these regions show a high degree of genetic admixture, characterized by an allele frequency cline running from NW Europe to East Asia. Although a proper differentiation has been established between the cline extremes of western Europe and South Asia, populations geographically located in between, i.e, Middle East and Mediterranean populations, require more detailed study in order to characterize their genetic background as well as to further understand their demographic histories. To initiate these studies, three ancestry informative SNP (AI-SNP) multiplex panels: the SNPforID 34-plex, Eurasiaplex and a novel 33-plex assay were used to describe the ancestry patterns of a total of 24 populations ranging across the longitudinal axis from NW Europe to East Asia. Different ancestry inference approaches, including STRUCTURE, PCA, DAPC and Snipper Bayes analysis, were applied to determine relationships among populations. The structure results show differentiation between continental groups and a NW to SE allele frequency cline running across Eurasian populations. This study adds useful population data that could be used as reference genotypes for future ancestry investigations in forensic cases. The 33-plex assay also includes pigmentation predictive SNPs, but this study primarily focused on Eurasian population differentiation using 33-plex and its combination with the other two AI-SNP sets.