Abstract:

Objective To investigate the ethnic origin of Chuanqing people, one of the largest unidentified ethnic groups in Guizhou, China, and analyze its genetic relationships with surrounding populations. Methods Based on a self-developed microhaplotype system, we conducted genotyping and analyzed the genetic distribution of microhaplotype loci and their forensic applicability in Chuanqing population in Guizhou Province. Using the microhaplotype data from different intercontinental populations and previously reported data from Han population living in Guizhou Province, we systematically investigated the genetic background of Chuanqing people through population genetic approaches, including genetic distance estimation, principal component analysis, and phylogenetic tree construction. Results Among the studied population, the number of haplotype per microhaplotype ranged from 6 to 25. The average expected heterozygosity (He), observed heterozygosity (Ho), power of discrimination (PD), and probability of exclusion (PE) were 0.8291, 0.8301, 0.9387, and 0.6593, respectively. The cumulative power of discrimination (CPD) and cumulative probability of exclusion (CPE) for these 33 loci were 1-2.62×10^-41 and 1-7.64×10^-17, respectively. Population genetic analyses revealed that the Chuanqing population had close genetic relationships with the East Asian populations, especially the local Guizhou Han population, Beijing Han population and the Han populations living in southern China. Conclusion The 33 microhaplotypes exhibit high levels of genetic diversity in the Guizhou Chuanqing population, highlighting their potentials for both forensic identification and parentage testing. The Han populations might have contributed a significant amount of genetic material to the Chuanqing population during the formation and development of the latter.

Key words: Chuanqing population, microhaplotype, genetic structure, forensic performance