Genetic convergence and diversity: A comparative analysis of Egyptian autosomal STR profiles within global populations

Abstract

Background and objective

Short Tandem Repeats (STRs) are widely used genetic markers for forensic identification and population genetics due to their high polymorphism. Given Egypt's unique position at the crossroads of Africa, Asia, and Europe, this study aims to analyze the allele frequency distribution of 15 autosomal STR loci in Egyptians and assess their genetic affinities with over 60 other global populations. The objective is to characterize Egypt's genetic profile, evaluate its intra- and inter-regional relationships, and contribute to a broader understanding of global STR clustering.

Methods

Allele frequency data for 15 autosomal STR loci were collected for the Egyptian population and compared with datasets from diverse global populations using Pearson's correlation coefficients, FST genetic distances, and Nei's genetic distance. Hierarchical clustering (UPGMA), allele frequency trajectories (AFTs), and Principal Coordinates Analysis (PCoA) were used to visualize genetic relationships. The findings were contextualized with prior studies of regional genetic structure for completeness and accuracy.

Results

The Egyptian STR profile showed moderate to high correlation (r > 0.85) with Middle Eastern, North African, and Southern European populations. FST and Nei's genetic distance values placed Egypt at a transitional point between Sub-Saharan African and Eurasian clusters. AFT plots revealed several loci with population-specific allele shifts, consistent with historical migration and admixture patterns. Notably, the results aligned with Omran et al.'s finding of genetic divergence between Northern and Southern Egyptians, and supported the tripartite global clustering model described in the 2014 worldwide STR analysis.

Conclusions

Egypt exhibits a unique genetic signature that reflects both African and Eurasian contributions, supporting its role as a genetic bridge population. These findings are valuable for forensic databases, population history, and anthropological studies. Future research should incorporate genome-wide SNP and uniparental marker analyses to further explore Egypt's internal diversity and its broader genetic connections.