Hi Everyone,

I have two VCF files: 1) VCF file containing SNPs from my population 2) Another VCF file with 1000 Genome SNPs data set from 26 populations.

I want to extract those variants that are found to be rare (<0.5%) within global samples (1000G) but common within my population (>5%). Can anyone please suggest a way how to do that? 


Thank you!
You can do this pretty easily using the GATK assuming that your VCF has the `AF` info field annotation. First annotate the variants in your VCF with the allele frequency of the variants in 1000 Genomes.

    java -jar $GATK -R reference.fasta -T VariantAnnotator -V input.vcf -o output_1.vcf --resource:onekg 1000genomes.vcf --expression onekg.AF

Then look for sites with AF > 0.05 and onekg.AF < 0.005 using GATK's SelectVariants.

    java  -jar GenomeAnalysisTK.jar -R reference.fasta -T SelectVariants --variant output_1.vcf -o output_2.vcf -select "AF > 0.05 && onekg.AF < 0.005"