Errors about read group (RG) information

delangeldelangel Posts: 71Dev mod
edited January 4 in Common Problems

What are read groups?

See the Dictionary entry on read groups.

Errors about missing or undefined read groups

As detailed in the FAQs about input requirements, GATK expects all read groups appearing in the read data to be specified in the file header, and will fail with an error if it does not find that information (whether there is no read group information in the file, or a subset of reads do not have read groups).

Typically you should read group information when you perform the original alignments (with e.g. BWA, which has an option to do so). So what do you do if you forgot to do that, and you don't want to have to rerun BWA all over again?

Solution

You can use a Picard tool called AddOrReplaceReadGroups to add the missing information to your input file.

Here's an example:

# throws an error
java -jar GenomeAnalysisTK.jar \
    -T HaplotypeCaller \
    -R reference.fasta \
    -I reads_without_RG.bam \
    -o output.vcf

# fix the read groups
java -jar picard.jar AddOrReplaceReadGroups \
    I= reads_without_RG.bam \
    O=  reads_with_RG.bam \
    SORT_ORDER=coordinate \
    RGID=foo \
    RGLB=bar \
    RGPL=illumina \
    RGSM=Sample1 \
    CREATE_INDEX=True

# runs without error
java -jar GenomeAnalysisTK.jar \
    -T HaplotypeCaller \
    -R reference.fasta \
    -I reads_with_RG.bam \
    -o output.vcf

Note that if you don't know what information to put in the read groups, you should ask whoever performed the sequencing or provided the BAM to give you the metadata you need.

Post edited by Geraldine_VdAuwera on
Sign In or Register to comment.