Genetic variation of 15 autosomal STR loci in the southern region population of KSA: A forensic DNA analysis study

Abstract

Objective Short tandem repeats (STRs) are highly polymorphic genetic markers with essential roles in forensic identification and paternity testing. Understanding the genetic diversity of STR loci in specific populations is crucial for accurate forensic applications. The aims of this study were to evaluate the genetic variation and forensic efficiency parameters for 15 autosomal STR loci in the southern region population of KSA. Methods Buccal swabs were collected from 150 unrelated native Saudi individuals from the southern region. DNA extraction was performed using Chelex 100, followed by quantification using a Quantifiler® Duo DNA Kit. STR amplification was conducted using an AmpFlSTR® Identifiler® Plus Kit, and capillary electrophoresis was performed with a Genetic Analyzer 3130. Statistical analyses were conducted using GeneAlex 6.5 and Powerstats v12 software. Results In total, 140 different alleles were observed across the 15 STR loci, with 6.57073827 × 1024 possible genotype combinations. The combined power of discrimination, probability of exclusion, combined match probability, and random match probability were 0.999788998, 0.999989779, 2.83258e-16, and 3.53034e+15, respectively. All loci had high polymorphic information content values, except for D7S820. Conclusion The high informativity observed for the 15 STR loci in the southern Saudi population demonstrates their usefulness for forensic and paternity testing applications. Keywords: DNA profiling, Forensic genetics, Population genetics, KSA, STR