VarBen Manual

User Manual:

Open the PDF directly: View PDF PDF.
Page Count: 6

DownloadVarBen Manual
Open PDF In BrowserView PDF
VarBen Manual
Introduction
VarBen is a software to add SNV/Indel, CNV and SV to BAM files, used for testing mutation callers and
pipelines.

Software Dependencies
1. samtools (http://samtools.sourceforge.net/)
2. pysam (http://code.google.com/p/pysam/ or pip install pysam)
3. bwa/tmap/novoalign

Known bugs and limitation
VarBen is under rapid development driven by suggesting and bug reports from the mutation calling community.
1. Currently, we are working on testing a new version of mutation editor for Ion Torrent plantform.
2. There is a bug in parallel function, the user cannot stop software via ctrl-C during it is running in
parallel mode.

Function 1. Mutation editor (muteditor.py)
usage: muteditor.py [-h] -m MUTFILE -b BAMFILE -r REFFASTA -o OUTDIR
--alignerIndex ALIGNERINDEX [-p PROCESS] [--seqer SEQER]
[-g] [--aligner ALIGNER] [--haplosize HAPLOSIZE]
[--mindepth MINDEPTH] [--minmutreads MINMUTREADS]
[--snpfrac SNPFRAC] [--minmapq MINMAPQ] [--multmapfilter]
[--diffcover DIFFCOVER] [--floworder FLOWORDER]
[--libkey LIBKEY] [--barcode BARCODE] [--tag]
Edit bamfile to spike in SNV, Indel, Complex, Substitution

Function 2. SV/CNV editor (sveditor.py)
usage: sveditor.py [-h] -m SVFILE -b BAMFILE -r REFFASTA -l READLENGTH -o
OUTDIR --alignerIndex ALIGNERINDEX [-p PROCESS]
[--seqer SEQER] [-g] [--aligner ALIGNER]
[--mindepth MINDEPTH] [--minmutreads MINMUTREADS]
[--minmapq MINMAPQ] [--multmapfilter]
[--floworder FLOWORDER] [--libkey LIBKEY]
[--barcode BARCODE] [--tag]
Edit bam file to spike in SV

1

Local optional arguments (only used in muteditor.py)
-m MUTFILE, --mutfile MUTFILE
Target regions to try and spike in a point mutation.
There are four types of snv/indel included in the software: snv, ins(insertion), del(deletion), Sub(Complex
mutation). The file format is shown as below.
#Chrom Start End AlleleFrequency Type AlternativeSequence
chr1 899778 899778 0.9 snv T
chr1 3712508 3712508 0.9 snv T
chr1 1158637 1158638 0.9 ins TAG
chr1 3397038 3397039 0.9 ins AGGTAG
chr1 6533124 6533126 0.9 del .
chr1 7910946 7910956 0.9 del .
chr7 55242467 55242481 0.3 Sub TTC ### Complex indel format: EGFR, c.2237_2251>TTC(p.E746_T751>VP)
How to determine the start and end position?
• For single nucleotide variant, the start and end site should be the same position in the genome.
• For short sequence insertion, the start and end site should has 1 base difference.
• For short sequence deletion, the start and end site shows the sequence start and end position which will
exclude from the sequencing reads.
• For Complex mutation, we want to using a short sequence A to instead of a sequence B, we should
put the sequence B’s start and end position in our mutation file.

Local optional arguments (only used in sveditor.py)
-m SVFILE, --svfile SVFILE
Target regions to try and spike in a SV or CNV.
There are six types of SV included in the software: inv(inversion), del(deletion), dup(duplication),
trans_chrom (whole arm translocate chromosome), trans_balance(balanced translocation chromosome),
trans_unbalance (insertional translocation chromosome).
del & inv format
#chrom

start end type

AF

chrX

12994966

12996009

del 0.6

chrX

20172336

20176010

del 0.6

2

chrX

105121310 105134706

del 0.6

chrX

108614726 108616334

del 0.6

chrX

13703890

14134046

inv 0.6

chrX

19975999

20064786

inv 0.6

chrX

32391049

32794255

inv 0.6

chrX

40994338

41012689

inv 0.6

dup format
#chrom

start end type

AF

dup_num

chr1

15808448

15814030

dup 0.6 3

chr1

16076907

16086182

dup 0.6 4

chr1

23665443

23711586

dup 0.6 3

chr1

28057278

28081157

dup 0.6 3

trans_chrom & trans_balance & trans_unbalance format
#CHR1 CHR1_start

CHR1_end

type

AF

CHR2

CHR2_start

chr10 7059511 7059511 trans_chrom 0.5 chr19 17396810
chr19 17327977

17327977

trans_chrom 0.5 chr3

CHR2_end
17396810

186528041 186528041

chr3

107598967 107598967 trans_chrom 0.5 chr7

38371959

38371959

chr1

31561816

31561816

trans_chrom 0.5 chr6

41297838

41297838

chr2

29754284

29754947

trans_balance 0.5 chr2

chr10 43608984

43609308

trans_unbalance 0.5 chr6

42522695

42523089

117640981 117640982

There are two types of CNV included in the software: gainand loss. The file format is shown as below.
#chrom

start end type

AF

cnv_type

chrX 66764255 66950650 cnv 2.5 gain
chr20 52186265 52200826 cnv 2 loss
-l READLENGTH, --readlength READLENGTH
The read length of BAM file.

3

Global optional arguments
-h, --help
To show the help message and exit.
-b BAMFILE, --bamfile BAMFILE
A BAM file to spike in mutations, the bam file should be sorted and indexed, the user also needs to provide a
BAM index .bai file with the same prefix name as BAM file. By default, the software considers the BAM
file consists by entirely paired-end reads, if a user needs to spike mutation in a BAM file which consists by
single-end reads, they need using the -single option.
-r REFFASTA, --reffasta REFFASTA
Genome reference, FASTA file with corresponding index .fai file which is generated by Samtools. The target
BAM file should be generated by the same reference file used in this option, especially the chromosome names
and lengths in the reference FASTA must be the same as in the BAM header. This FASTA file is used to
create pseudo reads near the editing poisition.
-o OUTDIR, --outdir OUTDIR
A output directory name for edited bam file and other information.
--alignerIndex ALIGNERINDEX
The index database sequences in the FASTA format of aligner. For example if the aligner is bwa, then bwa
index should be provided. This FASTA file is called by the external aligner.
-p PROCESS, --process PROCESS
Parallel mode: process number (default = 1)
--seqer SEQER
Define the seqer: illumina, life, BGI (default is illumina)
-g, --single
To declare that the input bam is single-ended (default is False)
--aligner ALIGNER
Choose an aligner from bwa, novoalign and tmap (default is bwa).

4

--haplosize HAPLOSIZE
The size of haplotype block to consider when adding more than 1 proximal mutation. (default = 0)
For example, if two SNVs are spiked in 5bp apart and -haplosize is 5 or greater, the two SNVs will be on
the same haplotype (i.e. share the same reads for reads covering both positions)
--mindepth MINDEPTH
The minimum depth of reads position which could be used as a spike in site. (default = 30)
For instance, if one spike in position reads depth is 25X (there are only 25 reads covered this position), the
VarBen software will drop this spike in position automatically due to the reads depth is not enough to add in
any mutation.
--minmutreads MINMUTREADS
The minimum number of reads to be edited in one position (default = 5).
VarBen will calculate the number of mutated reads by the allele frequency and the total number of reads in
the position. If the mutation reads number is less than 5, the software will not add in any mutation in this
position.
--snpfrac SNPFRAC
To avoid spike any mutatoin on top of exisiting heterozygous alleles, the heterozygous allele fraction set to
0.2 (default = 1)
--minmapq MINMAPQ
A read mapping quality less than MINMAPQ will not be considered to edit (default 20).
--multmapfilter
Any multi-mapped reads will not be considered to edit (default is True).
--diffcover DIFFCOVER
The coverage difference allowed between the input BAM and output BAM (default 0.9).
--floworder FLOWORDER
If seqer is life, a flower order of life sequence should be provided.
--libkey LIBKEY
If seqer is life, a libkey of life sequence should be provided.

5

--barcode BARCODE
If seqer is life, a barcode of life sequence should be provided.
--tag
Add tag to edited reads (default False).

6



Source Exif Data:
File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.5
Linearized                      : No
Page Count                      : 6
Page Mode                       : UseOutlines
Author                          : 
Title                           : VarBen Manual
Subject                         : 
Creator                         : LaTeX with hyperref package
Producer                        : pdfTeX-1.40.14
Create Date                     : 2019:06:04 15:33:57+08:00
Modify Date                     : 2019:06:04 15:33:57+08:00
Trapped                         : False
PTEX Fullbanner                 : This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013) kpathsea version 6.1.1
EXIF Metadata provided by EXIF.tools

Navigation menu