Convert a hg19 vcf to a b37d5 vcf - only handles chr1-22, X, Y & M

hg19_to_b37d5.sh

#!/bin/bash -e

if [[ ! -f "${1}" ]] ; then
    echo "File $1 does not exist, aborting."
    exit 1
fi
# Replace double digit chromosomes first
cmd="sed"
for i in `seq 10 22` `seq 1 9` X Y; do
    cmd="$cmd -e 's/chr$i/$i/g'"
done

# chrM to chrMT
cmd="$cmd -e 's/chrM/MT/g'"

# Add input and output
cmd="$cmd $1 > ${1%.vcf}.b37d5.vcf"

# Execute
echo $cmd
eval $cmd

cheers. shouldn't that be
's/chrM/MT/g'