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arXiv 1604.04280q-bio.GNstat.ML
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用于在深度、异质的下一代测序数据中检测罕见变异的变异推断

Variational inference for rare variant detection in deep, heterogeneous next-generation sequencing data

Fan Zhang, Patrick Flaherty

摘要:

罕见变异的检测对于理解混合样本中的遗传异质性非常重要。最近,下一代测序(NGS)技术已经能够以高分辨率鉴定混合样品中的单核苷酸变体(SNV)。然而,下一代测序所涉及的生物过程中固有的噪音需要使用统计方法来识别真正的罕见变异。我们提出了一种新的贝叶斯统计模型和变分期望最大化(EM)算法来估计非参考等位基因频率(NRAF),并确定SNV在异质细胞群体。我们表明,我们的变分EM算法具有可比的灵敏度和特异性相比,马尔可夫链蒙特卡罗(MCMC)抽样推理算法,是更低的覆盖率($27\times$和$298\times$)数据的测试计算效率。此外,我们表明,我们的模型与变分EM推理算法具有更高的特异性比许多国家的最先进的算法。在定向进化纵向酵母数据集的分析中,我们能够识别非参考等位基因频率的时间序列趋势,并检测尚未报道的新变体。我们的模型还检测到一个有益变异的出现早于先前所示,以及一对伴随变异。

英文摘要:

The detection of rare variants is important for understanding the genetic heterogeneity in mixed samples. Recently, next-generation sequencing (NGS) technologies have enabled the identification of single nucleotide variants (SNVs) in mixed samples with high resolution. Yet, the noise inherent in the biological processes involved in next-generation sequencing necessitates the use of statistical methods to identify true rare variants. We propose a novel Bayesian statistical model and a variational expectation-maximization (EM) algorithm to estimate non-reference allele frequency (NRAF) and identify SNVs in heterogeneous cell populations. We demonstrate that our variational EM algorithm has comparable sensitivity and specificity compared with a Markov Chain Monte Carlo (MCMC) sampling inference algorithm, and is more computationally efficient on tests of low coverage ($27\times$ and $298\times$) data. Furthermore, we show that our model with a variational EM inference algorithm has higher specificity than many state-of-the-art algorithms. In an analysis of a directed evolution longitudinal yeast data set, we are able to identify a time-series trend in non-reference allele frequency and detect novel variants that have not yet been reported. Our model also detects the emergence of a beneficial variant earlier than was previously shown, and a pair of concomitant variants.

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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