Familial relatedness (FR) and population structure (PS) are two major sources for genetic correlation. In the human population, both FR and PS can further break down into additive and dominant components to account for potential additive and dominant genetic effects. In this study, besides the classical additive genomic relationship matrix, a dominant genomic relationship matrix is introduced. A link between the additive/dominant genomic relationship matrices and the coancestry (or kinship)/double coancestry coefficients is also established. In addition, a way to separate the FR and PS correlations based on the estimates of coancestry and double coancestry coefficients from the genomic relationship matrices is proposed. A unified linear mixed model is also developed, which can account for both the additive and dominance effects of FR and PS correlations as well as their possible random interactions. Finally, this unified linear mixed model is applied to analyze two study cohorts from UK Biobank.

中文翻译：

---

遗传关联研究中家族关系和种群结构的统一线性混合模型

家族相关性（FR）和种群结构（PS）是遗传相关性的两个主要来源。在人群中，FR 和 PS 都可以进一步分解为加性和显性成分，以解释潜在的加性和显性遗传效应。在本研究中，除了经典的加性基因组关系矩阵外，还引入了显性基因组关系矩阵。还建立了加性/显性基因组关系矩阵和共同祖先（或亲属关系）/双共同祖先系数之间的联系。此外，提出了一种基于基因组关系矩阵中的共同祖先和双共同祖先系数的估计来分离FR和PS相关性的方法。还开发了统一的线性混合模型，这可以解释 FR 和 PS 相关性的加性和优势效应以及它们可能的随机相互作用。最后，这个统一的线性混合模型被应用于分析来自英国生物银行的两个研究队列。