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Ngs Question ~ Consensus

Could anybody point towards the direction in how to generate a “consensus” fasta sequence file including indels from a BAM file? Thanks

next-gen consensus bam
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updated by Jorge Amigo Jorge Amigo • written by Dirkjan Schokker • Dirkjan Schokker

3 answers

samtools mpileup -uf ref.fa aln.bam | bcftools view -cg - | vcfutils.pl vcf2fq > cns.fq

seqtk fq2fa cns.fq >cns.fa

seqtk was released in the latest samtools verion.

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written by Zhu • Zhu

I am fairly sure that this method will only include SNVs, but not INDELs. Please correct me if I'm wrong!

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written by Ian Ian

The GATK package has a utility called AlternateReferenceMaker to do this.

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written by Vitis Vitis

bcftools view -cg is now deprecated (version 1.1). bcftools call -vm should be used instead.

samtools mpileup -uf hg19.fa in.bam \
| bcftools call -vm -Oz - > out.vcf.gz
tabix -p vcf out.vcf.gz

bcftools consensus seems to be deprecated too (version 1.1). vcf-consensus may be used as an alternative:

samtools faidx hg19.fa chr22:29000000-29200000 \
| vcf-consensus out.vcf.gz \
| bgzip > out.fasta.gz

chr22:29000000-29200000 may be changed for any other region/s of interest

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written by Jorge Amigo Jorge Amigo

Coming in 4 year later, I've tried these lines of code for my single-end BAM file but the consensus sequence fills in gaps with bases from the reference.fasta file. Is there a way to just get a consensus of the BAM file or even the mpileup file to also keep gaps where there was no depth of coverage against the reference.fasta?

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written by DNAngel DNAngel

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