Alternative content
Performed with GATK :
java -Xmx8g -jar GenomeAnalysisTK.jar \
-T VariantsToTable \
-R reference.fa \
-V reference_genomes_GT.vcf \
-F CHROM -F POS -F REF -F ALT -GF GT \
-o reference_genomes_GT.table
multiple_sample.vcf should also be converted to multiple_sample_GT.table using this approach.