Genetic diversity of 23 STR loci in Guangxi Zhuang population and its phylogenetic relationship with other 25 populations

<b>Aim:</b> To estimate genetic diversity of 23 STR loci included in the DNA Typer^TM 25 Kit, and evaluate its effectiveness in forensic application. <b>Subjects and methods:</b> A total of 450 (251 males and 179 females) unrelated healthy individuals from Guangxi Zhuang population were amplified with DNA Typer^TM 25 Kit, isolated by a/the? 3730 analyzer and genotyped using the GeneMapper ID-X. Genetic parameters and population relationships were analysed. <b>Results:</b> Allele frequencies ranged from 0.001 to 0.5889. The combined power of discrimination (CPD) and the combined power of exclusion (CPE) of the 23 STR loci were 0.999999999999999999 and 0.999996765, respectively. No deviations from Hardy-Weinberg equilibrium and linkage disequilibrium were observed. Inter-population comparison based on Fst, PCA, genetic distance, phylogenetic trees and MDS showed that Zhuang population clustered with the population which holds a close geographic distance with Zhuang (Guangdong Han and Hainan Li populations). <b>Conclusions:</b> Our study indicated that the 23 autosomal STR loci included in DNA Typer^TM 25 Kit can be used as forensic tools for individual identification and parentage testing. Moreover, the result of our mass investigation will enrich the forensic database of Chinese populations and serve for further study of the origin of anthropology.

**研究目的**：评估DNA Typer™25试剂盒所涵盖的23个短串联重复序列（Short Tandem Repeat，STR）位点的遗传多样性，并评价其在法医鉴定中的应用效能。**研究对象与方法**：本研究共纳入450名来自广西壮族人群的无关健康个体（其中男性251名，女性179名），采用DNA Typer™25试剂盒进行扩增，通过3730型遗传分析仪分离扩增产物，并使用GeneMapper ID-X软件进行基因分型。随后对遗传参数及人群遗传关系展开分析。**研究结果**：本研究中，等位基因频率分布范围为0.001至0.5889。23个STR位点的累计个体识别力（combined power of discrimination，CPD）与累计非父排除率（combined power of exclusion，CPE）分别为0.999999999999999999与0.999996765。未观察到偏离哈迪-温伯格平衡及连锁不平衡的情况。基于固定指数（Fst）、主成分分析（PCA）、遗传距离、系统发育树及多维标度分析（MDS）的人群间比较结果显示，壮族人群与地理距离相近的人群（广东汉族人群及海南黎族人群）聚为一支。**研究结论**：本研究证实，DNA Typer™25试剂盒所涵盖的23个常染色体STR位点可作为法医个体识别及亲权鉴定的有效工具。此外，本大规模群体调查的研究结果将丰富中国人群法医遗传数据库，为人类学起源相关研究提供参考依据。