Afghanistan: conduits of human migrations identified using AmpFlSTR markers.

This study describes autosomal STR profiles of the populations of South and North Afghanistan. A total of 188 unrelated individuals residing north (n = 42) and south (n = 146) of the Hindu Kush Range within the territory of Afghanistan were examined against the background of 54 geographically targeted reference populations from Eurasia and North East Africa. The main objective of this study was to investigate longitudinal gene flow across the Hindu Kush Range and Eurasia. Genetic differentiation tests between North and South Afghanistan generated insignificant genetic differences for all loci. Multidimensional scaling (MDS) plots based on Fst distances and Neighbor-Joining (N-J) analysis indicated genetic affinities between the Afghani groups and Indian/Near East/West Asian populations. Admixture and Structure analyses demonstrate a gradient of genetic continuity within a major east to west cline that includes North and South Afghanistan as intermediate populations. Overall, although Afghanistan is surrounded by a number of natural barriers, instead of an isolated territory, it has been a genetically porous region providing a migrational nexus to the rest of Eurasia.