Differences in the Gene Pool Structure of Five Populations of Dagestan Revealed Using X-Chromosomal Microsatellite Markers

Abstract X-STR markers are highly informative for kinship testing in complex cases. According to the recommendations of the International Society for Forensic Geneticists (ISFG), for the correct use of X-chromosomal markers in practice, it is necessary to take into account the genetic structure of the population to which the studied individuals belong. This article presents the results of a genetic structure analysis of five Dagestan populations (Tsez, Tsakhur, Karata, Archin, and Dargin) using 15 X-STR markers (HPRTB, DXS6797, DXS6804, GATA165B12, DXS6810, DXS8377, DXS7133, DXS7424, DXS7423, DXS6789, GATA31E08, DXS10079, DXS10103, DXS7132, DXS9895). The analysis revealed differences in population differentiation levels, supported by Fst values and AMOVA results, particularly among isolated populations such as Archin and Tsez. A study of linkage disequilibrium structure confirmed population variability in the distribution of linked loci. The article provides reference data for X-chromosomal markers, including allele and haplotype frequencies, which significantly enhance the toolkit for genetic expertise. These data improve the accuracy and reliability of kinship probability calculations in five indigenous Dagestan populations.