cat data.chm13/00000000000000000000000000000013.vcf \
    <(grep -v '^#' data.chm1/00000000000000000000000000000001.vcf) \
    > data.chmboth/00000000000000000000000000000003_unsorted.vcf

grep -E '^chr[0-9]+\t|^chrX\t|^#' \
      data.chmboth/00000000000000000000000000000003_unsorted.vcf \
      > data.chmboth/00000000000000000000000000000003_unsorted_filtered.vcf

bcftools sort data.chmboth/00000000000000000000000000000003_unsorted_filtered.vcf -o data.chmboth/00000000000000000000000000000003.vcf
