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Activity Number: 312 - Recent Methods Development for Sequence-Based Association Studies
Type: Contributed
Date/Time: Tuesday, July 31, 2018 : 8:30 AM to 10:20 AM
Sponsor: Section on Statistics in Genomics and Genetics
Abstract #330294 Presentation
Title: Methods and Study Design for Integrating External Controls with Allele Frequencies
Author(s): Megan Sorenson* and Audrey Hendricks
Companies: University of Colorado Denver and University of Colorado - Denver
Keywords: external controls; rare variants; sequencing; summary level data; iECAT; ProxECAT
Abstract:

Within statistical genetics, there is an ever-increasing availability of publicly available summary level data such as allele or genotype frequencies. This information has the potential to be used in case-control association tests to increase the sample size and possibly power of a study and can allow resources to be focused on sequencing cases. However, differences between the internal and external samples can cause considerable confounding. Here, we compare two methods that use frequency level data from external controls while adjusting for batch effects: Integrating External Controls into Association Test (iECAT) and Proxy External Controls Association Test (ProxECAT). We compare the type I error and power of these methods to a standard case-control test across a variety of simulation scenarios where we change parameters such as sample size, confounding effects, and genetic region. Combined with current and projected sequencing costs, we estimate and compare the costs and power of study designs with various sizes of internal and external control samples. This guidance is especially important for studies with limited resources.


Authors who are presenting talks have a * after their name.

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