RNA Panel

The DRAGEN recipe includes the recommended pipeline specific commands.

  
/opt/dragen/$VERSION/bin/dragen         #DRAGEN install path 
--ref-dir $REF_DIR                      #path to DRAGEN pangenome hashtable 
--output-directory $OUTPUT 
--intermediate-results-dir $PATH        #e.g. SDD /staging 
--output-file-prefix $PREFIX 
# Inputs 
--fastq-list $PATH                      #see 'Input Options' for FQ, BAM or CRAM 
--fastq-list-sample-id $STRING 
# Mapper 
--enable-rna true 
--annotation-file $GTF                  #GTF or GFF3 format 
--enable-map-align true                 #required for RNA/scRNA 
--enable-map-align-output true          #optionally save the output BAM 
--enable-sort true                      #default=true 
--enable-duplicate-marking true         #default=true 
# Small variant caller 
--enable-variant-caller true 
--vc-target-bed $VC_TARGET_BED 
# RNA Quantification 
--enable-rna-quantification true 
--rna-library-type A                    #see 'RNA Quant' 
--rna-quantification-gc-bias true 
# RNA Splice Variants 
--enable-rna-splice-variant true 
--rna-splice-variant-regions $PATH 
# RNA Gene Fusions 
--enable-rna-gene-fusion true 
--rna-gf-enriched-regions $PATH         #see 'RNA Fusion' 

Notes and additional options

Hashtable

For DRAGEN RNA/scRNA runs, it is recommended to use the linear hashtable.

Input options

DRAGEN input sources include: fastq list, fastq, bam, or cram.

FQ list Input

--fastq-list $PATH 
--fastq-list-sample-id $STRING 

FQ Input

--fastq-file1 $PATH 
--fastq-file2 $PATH 
--RGSM $STRING 
--RGID $STRING 

BAM Input

--bam-input $PATH 

CRAM Input

--cram-input $PATH 

Mapping and Aligning

Option
Description

--enable-map-align true

Optionally disable map & align (default=true).

--enable-map-align-output true

Optionally save the output BAM (default=false).

Duplicate Marking

Option
Description

--enable-duplicate-marking true

By default, DRAGEN marks duplicate reads and exclude them from variant calling.

--enable-positional-collapsing true

Alternative to --enable-duplicate-marking=true. Instead of discarding duplicate reads, DRAGEN can optionally perform positional collapsing, merging them into higher-quality consensus reads. This is beneficial for small panels without UMIs and coverage between 300X and 1000X. However, it's slower than standard duplicate marking and less effective on samples with coverage lower than 300X. For very high coverage (1000X+), avoid it due to potential read collisions. For high-sensitivity panels with 1000X+ coverage, consider using UMIs.

RNA Variant Calling

Option
Description

--vc-target-bed $PATH

Restrict the variants called to a target bed. For WTS, a bed file specifying the gene-coding regions should be provided to avoid calling erroneous variants in non-coding regions due to noisy reads.

RNA Quant

Option
Description

--rna-library-type

Set the library according to the read orientations. Set to 'A' to auto detect the correct read orientation. Alternatively select 'IU', 'ISR', 'ISF', 'U', 'SR', or 'SF'.

RNA Splice

Option
Description

--rna-splice-variant-normals $PATH

Optional setting list of normal splice variants that will be used filter false positive calls. The file should be a tab separated file with the following first four columns: (1) contig name, (2) first base of the splice junction (1-based), (3) last base of the splice junction (1-based), (4) strand (0: undefined, 1: +, 2: -).

--rna-splice-variant-regions $PATH

Target region bed file. Required for panels. The name of the region must be specified in the fourth column.

RNA Fusion

Option
Description

--rna-gf-enriched-regions $PATH

For panels, the list of enriched genes should be set, either as a list of genes or a list of regions in BED format.

RNA Amplicon

To enable RNA amplicon, set:

  • --enable-rna-amplicon true, and

  • --amplicon-target-bed $PATH.

If RNA amplicon mode is enabled and the amplicon bed file already includes the gene name, then it is not required to set the ENRICH options option, since DRAGEN will read the enriched genes names from the amplicon BED file (fifth column).

Last updated

Was this helpful?