New VEP does not handle Delly SV VCFs

[ckandoth]

The older VEP v86 and v88 seem to work fine with vcf2maf v1.6.15 and generate a proper MAF for the SVs. But VEP v92 with vcf2maf 1.6.16 produces an empty MAF. Most likely because the newer VEP handles ALT=<SV_TYPE> format differently.