Test-drive the GATK tools and Best Practices pipelines on Terra
Check out this blog post to learn how you can get started with GATK and try out the pipelines in preconfigured workspaces (with a user-friendly interface!) without having to install anything.
Exploring parameter space with hard filters (VariantFiltration)
I am doing an analysis on chimp variants, and do not have enough variants to train the model in order to perform VQSR. I am using hard filters at this point, as per the recommendation. I keep reading that the recommended cutoff values are only recommendations and that I should expect to tweak the parameters further. However, how do I do this in an effective manner? I'm just not sure how to approach exploring the parameter space.
Should I try out different values around the recommended cutoffs and, down the line, analyze how many mutations I get/calculate certain values for quality control and check that they agree with what is expected (CpG transition rate, and so on)? Is there a way to inspect the data to see whether it is behaving well, or do I have to wait until down the line to see how things are going? Any insight into this would help tremendously.