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arXiv 1701.01286stat.AP
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用于遗传关联研究的强大极端表型抽样设计和评分检验

Powerful extreme phenotype sampling designs and score tests for genetic association studies

Thea Bjørnland, Anja Bye, Einar Ryeng, Ulrik Wisløff, Mette Langaas

摘要:

我们考虑横断面遗传关联研究(常见和罕见变异),其中非遗传信息是可用的,或可行的获得$N$个人,但它是不可行的基因型所有$N$个人。我们考虑连续可测量的高斯性状(表型)。与随机选择$n$个体相比,对$n<N$极端表型个体进行基因分型可以产生更好的功效来检测表型-基因型关联。如果观察到的表型高于指定阈值或低于指定阈值,则我们将一个人定义为具有极端表型。我们考虑一个模型,这些阈值可以为每个人量身定制。经典的极端抽样设计是为所有个体设置相等的阈值。我们介绍了一种设计($z$ -极端抽样),其中个性化的阈值定义的基础上的残差的回归模型,包括只有非遗传(完全可用)的信息。我们推导出仅分析$n$极端情况(完整病例分析)和分析中包括$N-n$非极端情况(所有病例分析)的非遗传信息的情况下的评分检验。对于经典设计,全案例分析通常比全案例分析更强大。对于$z$极端的样本,我们表明,所有的情况下,完整的情况下测试是同样强大的。模拟和数据分析还表明,$z$ -极端抽样至少是强大的经典极端抽样设计和经典设计被证明是有时不如随机抽样。还讨论了极端表型的二分化方法。

英文摘要:

We consider cross-sectional genetic association studies (common and rare variants) where non-genetic information is available, or feasible to obtain for $N$ individuals, but where it is infeasible to genotype all $N$ individuals. We consider continuously measurable Gaussian traits (phenotypes). Genotyping $n<N$ extreme phenotype individuals can yield better power to detect phenotype-genotype associations, as compared to randomly selecting $n$ individuals. We define a person as having an extreme phenotype if the observed phenotype is above a specified threshold or below a specified thresholds. We consider a model where these thresholds can be tailored to each individual. The classical extreme sampling design is to set equal thresholds for all individuals. We introduce a design ($z$-extreme sampling) where personalized thresholds are defined based on the residuals of a regression model including only non-genetic (fully available) information. We derive score tests for the situation where only $n$ extremes are analyzed (complete case analysis), and for the situation where the non-genetic information on $N-n$ non-extremes is included in the analysis (all case analysis). For the classical design, all case analysis is generally more powerful than complete case analysis. For the $z$-extreme sample, we show that all case and complete case tests are equally powerful. Simulations and data analysis also show that $z$-extreme sampling is at least as powerful as the classical extreme sampling design and the classical design is shown to be at times less powerful than random sampling. The method of dichotomizing extreme phenotypes is also discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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