Evaluation of skin-related variants in African ancestry populations and their role in personal identification

Abstract

Pigment-related genetic variants point out their role in personal identification as they can be considered predictors suitable for Forensic DNA Phenotyping (FDP) and mounting evidence suggest also their bio-geographic inferential power for gaining information about the individual geographical origin. As they could be regarded as AIMs (Ancestry Informative Markers) they are powerful tools for inferring genetic composition of admixed population. Despite the huge range of skin tones across our species, little is known about genetic basis in global population and particularly our knowledge is less precise for those showing a complex historical and genomic background. The current research aims to explore the allelic status in several SNPs mapped in selected genes known to be involved in skin pigmentation: OCA2, HERC2, SLC45A2, SLC24A5 and two intergenic regions between BEND7/PRPF18 and EIF2S2/ASIP. The genetic evaluation has been performed on selected African and African derived populations: Fon, Dendi, Bariba and Berba communities from Benin, and Afroecuadorians. Data integration has been made up merging genotypic results with available information from major biological data warehouse as Phase 3–1000 Genomes Project or International HapMap Project in order to obtain a selected populations panel useful for their use as inferential model training set to test the likelihood of correct assignment to geographically differentiated human groups. The proposed variants panel seems to properly interpret the geographic variation and some new interesting evidence could be pointed out in African mixed populations, that seem to be differentially distributed if the total panel is considered. Understanding human pigmentation architecture can provide fundamental insight into genetic interaction of complex traits and the relationship between environmental adaptation and population history. In addition, the results support the use of phenotypic inference along with bio-geographical ancestry information as valid auxiliary tools in personal identification.