Laboratório de Genética Humana e Médica, Universidade Federal do Pará, Belém, Pará, Brazil.
Hum Mutat. 2010 Feb;31(2):184-90. doi: 10.1002/humu.21159.
Estimating the proportions of different ancestries in admixed populations is very important in population genetics studies, and it is particularly important for detecting population substructure effects in case-control association studies. In this work, a set of 48 ancestry-informative insertion-deletion polymorphisms (INDELs) were selected with the goal of efficiently measuring the proportions of three different ancestries (sub-Saharan African, European, and Native American) in mixed populations. All selected markers can be easily analyzed via multiplex PCR and detected with standard capillary electrophoresis. A total of 593 unrelated individuals representative of European, African, and Native American parental populations were typed, as were 380 individuals from three Brazilian populations with known admixture patterns. As expected, the interethnic admixture estimates show that individuals from southern Brazil present an almost exclusively European ancestry; Afro-descendant communities in the Amazon region, apart from the major African contribution, present some degree of admixture with Europeans and Native Americans; and a sample from Belém, in the northeastern Amazon, shows a significant contribution of the three ethnic groups, although with a greater European proportion. In summary, a panel of ancestry-informative INDELs was optimized and proven to be a valuable tool for estimating individual and global ancestry proportions in admixed populations. The ability to accurately infer interethnic admixtures highlights the usefulness of this marker set for assessing population substructure in association studies, particularly those conducted in Brazilian and other Latin American populations sharing trihybrid ancestry patterns.
估算混合人群中不同祖先的比例在群体遗传学研究中非常重要，特别是在病例对照关联研究中检测人群亚结构效应时更为重要。在这项工作中，选择了一组 48 个具有祖先信息的插入缺失多态性（INDELs），旨在有效地测量混合人群中三种不同祖先（撒哈拉以南非洲、欧洲和美洲原住民）的比例。所有选定的标记都可以通过多重 PCR 轻松分析，并通过标准毛细管电泳检测。对来自欧洲、非洲和美洲原住民父母群体的 593 个无关个体以及具有已知混合模式的 380 个来自三个巴西群体的个体进行了分型。正如预期的那样，族裔间混合估计表明来自巴西南部的个体几乎完全具有欧洲血统；亚马逊地区的非裔社区除了主要的非洲贡献外，还与欧洲人和美洲原住民有一定程度的混合；来自亚马逊东北部贝伦的一个样本显示了三个群体的显著贡献，尽管欧洲群体的比例更大。总之，优化了一组具有祖先信息的 INDELs，并证明它是一种用于估算混合人群中个体和总体祖先比例的有效工具。准确推断族裔间混合的能力突出了该标记集在关联研究中评估人群亚结构的有用性，特别是在具有三杂交祖先模式的巴西和其他拉丁美洲人群中进行的研究。
