I am working with some 1KG VCF files and I just extracted biallelic SNPs using the
vcflib library. However, I noticed that some SNPs have this additionally field: "EX_TARGET"
...SAS_AF=0.001;VT=SNP;EX_TARGET GT 0|0 0|0...
I've googled it and however I haven't found it anywhere on the 1KG documentation. I just found one website that mentioned these were not reliable? What does it mean? Are these only SNPs on exons?