Allele frequencies and forensic parameters based upon 23 Autosomal STRs loci of 406 Cambodian individuals in Thailand

This study evaluated the allele frequencies and forensic parameters of 23 autosomal short tandem repeat (aSTR) loci in 406 genotypes from a Cambodian population residing in Thailand. The loci were stored in the Thailand DNA database of the Police Forensic Science Center 1, Pathum Thani. No significant deviations from Hardy-Weinberg equilibrium were found for any loci after applying the Bonferroni correction (p > 0.002). SE33 exhibited the highest degree of genetic polymorphism, making it the most informative locus, while TPOX was the least informative. The combined power of discrimination (CPD) and combined power of exclusion (CPE) for the 23 aSTR loci were both at 0.9999. A phylogenetic tree was constructed to compare the Cambodian population with four other populations (Laotian, Thai, Vietnamese, and Malaysian). The results showed that the Cambodian population clustered with the other four populations, with the Laotian population being the most closely related. However, six dominant alleles unique to the Cambodian population in Thailand were identified, distinguishing this population from the Laotian, Thai, Vietnamese, and Malaysian populations. Moreover, two of these dominant alleles were exclusively found in the Cambodian population in Thailand and were not present in any of the 22 other compared populations. Therefore, the allele frequency data from this study can serve as a reference for identifying allele differences in other populations and can further enhance the accuracy of forensic human identification and kinship testing.