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.
Use CombineVariants with chromosome-specific vcf files
I have generated vcf files using GenotypeGVCFs; each file contains variants corresponding to a different chromosome. I would like to use VQSR to perform the recalibration on all these data combined (for maximum power), but it seems that VQSR only takes a single vcf file, so I would have to combine my vcf files using CombineVariants. Looking at the documentation for CombineVariants, it seems that this tool always produces a union of vcfs. Since each vcf file is chromosome-specific, there are no identical sites across files. My questions are: Is CombineVariants indeed the appropriate tool for me to merge chromosome-specific vcf files, and is there any additional information that I should specify in the command-line when doing this? Do I need to run VariantAnnotator afterwards (I would assume not, since these vcfs were generated using GenotypeGVCFs and the best practices workflow more generally)? I just want to be completely sure that I am proceeding correctly.
Thank you very much in advance,