he lof_sieve tool reports the fractional position (e.g. 0.05 for the first 5%) of the mutation in the amino acid sequence. In addition, it also reports the predicted function of the transcript so that one can segregate candidate LoF variants that affect protein_coding transcripts from processed RNA, etc.
gemini lof_sieve chr22.low.exome.snpeff.100samples.vcf.db