Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China; Key Laboratory of Forensic Genetics, Institute of Forensic Science, Ministry of Public Security, Beijing 100038, PR China.
Forensic Sci Int Genet. 2014 Jan;8(1):187-94. doi: 10.1016/j.fsigen.2013.09.004. Epub 2013 Sep 18.
Inferring the ancestral origin of DNA samples can be helpful in correcting population stratification in disease association studies or guiding crime investigations. Populations throughout the world vary in appearance features and biological characteristics. Based on this idea, we performed a genome-wide scan for SNPs within genes that are related to physical and biological traits. Using the HapMap database, we screened 52 genes and their flanking regions. Thirty-five SNPs that displayed highly contrasting allele frequencies (F(st)>0.3, linkage disequilibrium r(2)<0.2, and Hardy-Weinberg equilibrium P>0.001) among Africans, Europeans, and East Asians were selected and validated. A multiplexed assay was developed to genotype these 35 SNPs in 357 individuals from 10 populations worldwide. This panel provided accurate estimates of individual ancestry proportions with balanced discriminatory power among the three continental ancestries: Africans, Europeans, and East Asians. It also proved very effective in evaluating admixed populations living in joint regions of continents (e.g., Uyghurs and Indians) and discriminating some subpopulations within each of the three continents. Structure analysis was performed to establish and evaluate the panel of ancestry-informative markers, and the components of each population were also described to indicate the structural composition. The 21 population structures in our study are consistent with geographic patterns, and individuals were properly assigned to their original ancestral populations with proportion analyses and random match probability calculations. Thus, the panel and its population information will be useful resources to minimize the effects of population stratification in association analyses and to assign the most likely origin of an unknown DNA contributor in forensic investigations.
推断 DNA 样本的祖先来源有助于纠正疾病关联研究中的群体分层或指导犯罪调查。世界各地的人群在外观特征和生物特征上存在差异。基于这一想法，我们对与身体和生物特征相关的基因内的 SNPs 进行了全基因组扫描。利用 HapMap 数据库，我们筛选了 52 个基因及其侧翼区域。在非洲人、欧洲人和东亚人之间，我们选择并验证了 35 个具有高度差异等位基因频率（F(st)>0.3，连锁不平衡 r(2)<0.2，Hardy-Weinberg 平衡 P>0.001）的 SNP。开发了一种多重测定法来对来自全球 10 个群体的 357 个人的这 35 个 SNP 进行基因分型。该面板在三个大陆祖先（非洲人、欧洲人和东亚人）之间提供了个体祖先比例的准确估计，具有平衡的辨别力。它还在评估居住在大陆共同地区的混合人群（如维吾尔族和印度人）以及区分三个大陆中的一些亚群方面非常有效。进行了结构分析以建立和评估祖先信息标记面板，还描述了每个群体的组成部分以指示结构组成。我们研究中的 21 个群体结构与地理模式一致，并且通过比例分析和随机匹配概率计算，个体被正确分配到其原始祖先群体中。因此，该面板及其群体信息将是有用的资源，可以最大限度地减少关联分析中群体分层的影响，并在法医调查中确定未知 DNA 供体最可能的来源。
