UnifiedGenotyper doesn't generate 1 vcf per sample when bams from multiple subjects are input
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we are running tests trying to get UG to produce 1 vcf per sample when inputting bams from multiple subjects. our situation is complicated slightly by the fact that each sample has 3 bams. when we input all 6 bams into UG, hoping to output 2 vcfs (1 per sample) we instead get a single vcf. we found some relevant advice in this post: http://gatkforums.broadinstitute.org/discussion/2262/why-unifiedgenotyper-treat-multiple-bam-input-as-one-sample but still haven't solved the issue.

details include: 1) we are inputting 6 bams for our test, 3 per sample for 2 samples. 2) bams were generated using Bioscope from targeted capture reads sequenced on a Solid 4. 3) as recommended in the post above we checked out the @RG statements in the bam headers using Samtools -- lines for the 6 bams are as follows:

sample 1:

@RG ID:20130610202026358 PL:SOLiD PU:bioscope-pairing LB:75x35RR PI:148 DT:2013-06-10T16:20:26-0400 SM:S1

@RG ID:20130611214013844 PL:SOLiD PU:bioscope-pairing LB:75x35RR PI:148 DT:2013-06-11T17:40:13-0400 SM:S1

@RG ID:20130613002511879 PL:SOLiD PU:bioscope-pairing LB:75x35RR PI:147 DT:2013-06-12T20:25:11-0400 SM:S1

sample 2:

@RG ID:20130611021848236 PL:SOLiD PU:bioscope-pairing LB:75x35RR PI:151 DT:2013-06-10T22:18:48-0400 SM:S1

@RG ID:20130612014345277 PL:SOLiD PU:bioscope-pairing LB:75x35RR PI:151 DT:2013-06-11T21:43:45-0400 SM:S1

@RG ID:20130613085411753 PL:SOLiD PU:bioscope-pairing LB:75x35RR PI:150 DT:2013-06-13T04:54:11-0400 SM:S1

Based on the former post, I would have expected each of these bams to generate a separate vcf as it appears the ids are all different (which would not have been desirable either, as we are hoping to generate 2 vcfs in this test). Thus, it is not clear if/how we should use Picard tool AddOrReplaceReadGroups to modify the @RG headers?

Does that make sense? Any advice?


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