I am running one burden test per enhancer region in about 14,000 enhancers.
So, I could correct by taking a threshold of 0.05 / 14000.
However, some of these enhancers are actually exactly the same, but being tested twice due to being active in more than one cell type. Others are distinct enhancers, but the sequence is anywhere from 5-95% overlapping another enhancer.
My question is, how should I go about establishing a bonferonni-corrected threshhold for association?
Clearly this are not independent tests, which is normally when a BCT is invoked. So what is the best fix here?
I want to run all the tests because I want to know if the same, or similar, enhancers are acting in different cells, so I do not wish the redundancy before running the tests. Rather, I seek a way of altering the threshhold in such a way that recognizes that in some case it is the same test being run, it is just that the enhancer is active in 2 (or more) cell types.
1 answer
I am not familiar with burden tests and the data you have so what I suggest may not apply. Concerning overlapping regions, I would decide on how much overlap is acceptable to call them different enhancers. For example, a 95% overlap is probably within the error of enhancer boundary definition and could be considered the same enhancer but a 5% overlap means the sequences are essentially different and so probably represent different enhancers. Alternatively, you could try merging all overlapping regions into a set of discontinuous regions and test these. Concerning the test, my first thought was that you could replace the Bonferonni correction with a FDR correction. On second thought though, assuming you have data for several cell types for each enhancer, I think I would try some sort of multivariate analysis to identify which enhancers are active then do a post-hoc analysis to find out in which cells they're active.
Log in to answer this question.
Here is some sample output of genomic regions: