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  • lynnatsd
    Junior Member
    • Jun 2011
    • 2

    question for genotying with bcftools

    hi,

    I am trying to call the genotypes with the mpileup output using bcftools. I found very weird for one SNP, I actually have heterozygous and the DP4 field also indicate so, but the ALT. column output as ".". See example below -

    chr10.fa 128479589 . T . 12.3 . DP=147300;AF1=0.496;CI95=0.5,0.5;DP4=60853,1,79189,2;MQ=59;FQ=-9.5;PV4=1,0,0,0.19 PL 18

    has anybody have the same problem and know a reason for this? thanks!

    - lynn
    ###########################
    The command I am generating the .vcf is

    samtools mpileup -ugf hg19.fasta -C50 -d 10000000 test.bam | bcftools view -cg - > test.vcf

    samtools and bcftools come from samtools-0.1.14
  • blue mood
    Member
    • Jul 2011
    • 21

    #2
    i have the same problems ,can anyone give some suggestions?

    Comment

    • nilshomer
      Nils Homer
      • Nov 2008
      • 1283

      #3
      Look at "DP4=60853,1,79189,2;". That says to me that the reads are mostly on the same genomic strand. This is very unlikely unless built-in your experiment design, and is better explained by mis-mapping. That is why it is not being called with high confidence.

      Comment

      • win804
        Member
        • Apr 2010
        • 18

        #4
        Originally posted by nilshomer View Post
        Look at "DP4=60853,1,79189,2;". That says to me that the reads are mostly on the same genomic strand. This is very unlikely unless built-in your experiment design, and is better explained by mis-mapping. That is why it is not being called with high confidence.
        Then why PV4 for strand bias is 1? I suppose the p-value for strand bias should be very small? I am sorry, probably I misunderstand the p-value for strand bias. but can you enlighten me please? Thanks.

        Comment

        • nilshomer
          Nils Homer
          • Nov 2008
          • 1283

          #5
          Originally posted by win804 View Post
          Then why PV4 for strand bias is 1? I suppose the p-value for strand bias should be very small? I am sorry, probably I misunderstand the p-value for strand bias. but can you enlighten me please? Thanks.
          I think the -S option in mpileup gives strand bias p-values. Is that turned on?

          Comment

          • win804
            Member
            • Apr 2010
            • 18

            #7
            Thanks Heng.
            That answers my question.

            Comment

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