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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,

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