I want to find copy number variation in my samples. Samples are of psychiatry patients and I have done exome sequencing on NextSeq. For this purpose I want analyse samples with excavator. The problem is choosing control sample for this analysis. Can I choose ExAC samples? Will it be right to choose samples that are run on HiSeq? Also can you suggest some other tools for this purpose. As most tools available for CNV analysis are for tumor analysis and based on R.