Suggested Pipeline Configuration 5.2.7 - Illumina/Pisces GitHub Wiki
Example Variant Calling Pipeline:
Components:
Application | Function | Somatic | Germline | Notes |
---|---|---|---|---|
forthcoming | indel realignment | yes | yes | This is slow. 2-3x slower than the whole Pisces step. You can skip it if you don't need the precision. Gets rid of a lot of false positives if the upstream aligner tends to make a lot of judgment errors. |
Stitcher | stitches reads | yes | yes | reconciles pairs of reads into single consensus reads,reduces FP due to noise, reduces FN due to strand bias, only works with paired end sequencing |
Pisces | variant calling | yes | yes | use -ThreadByChr for faster performance but greater memory hit. Use qsub on the cluster, works fine with UMIs or for catching variants < 0.01%, so long as the data quality supports this and Pisces is properly configured. |
Q Score Recalibration | Downgrade Q score for poor samples | yes | no | Run before or after scylla. Somatic calling is quite sensitive to sample degradation, germline calling less so. Gets rid of a lot of false positives if the samples has a lot of FFPE or oxidative damage that otherwise would dominate the variant calls. |
Scylla | long range phasing | yes | yes | Default configuration works well with somatic. Special germline settings: ploidy=diploid, crushvcf=true, dist=5;must load the same bam that pisces does. Ie, if Pisces acts on a stitched or re-aligned bam, then so should Scylla,Turn off upstream MNV calling by Pisces. |
Settings:
https://github.com/Illumina/Pisces/wiki/Pisces-Quick-Start-5.2.7