As reported by Menachem Fromer: a critical bug in AFCalcResult:
Specifically, the implementation:
public boolean isPolymorphic(final Allele allele, final double log10minPNonRef) {
return getLog10PosteriorOfAFGt0ForAllele(allele) >= log10minPNonRef;
}
seems incorrect and should probably be:
getLog10PosteriorOfAFEq0ForAllele(allele) <= log10minPNonRef
The issue here is that the 30 represents a Phred-scaled probability of *error* and it's currently being compared to a log probability of *non-error*.
Instead, we need to require that our probability of error be less than the error threshold.
This bug has only a minor impact on the calls -- hardly any sites change -- which is good. But the inverted logic effects multi-allelic sites significantly. Basically you only hit this logic with multiple alleles, and in that case it'\s including extra alt alleles incorrectly, and throwing out good ones.
Change was to create a new function that properly handles thresholds that are PhredScaled quality scores:
/**
* Same as #isPolymorphic but takes a phred-scaled quality score as input
*/
public boolean isPolymorphicPhredScaledQual(final Allele allele, final double minPNonRefPhredScaledQual) {
if ( minPNonRefPhredScaledQual < 0 ) throw new IllegalArgumentException("phredScaledQual " + minPNonRefPhredScaledQual + " < 0 ");
final double log10Threshold = Math.log10(QualityUtils.qualToProb(minPNonRefPhredScaledQual));
return isPolymorphic(allele, log10Threshold);
}
-- Multi-allelic variants are split into their bi-allelic version, trimmed, and we attempt to provide a meaningful genotype for NA12878 here. It's not perfect and needs some discussion on how to handle het/alt variants
-- Adding splitInBiallelic funtion to VariantContextUtils as well as extensive unit tests that also indirectly test reverseTrimAlleles (which worked perfectly FYI)
-- Idea is simply to create a persistent database of all TP/FP sites on chr20 in NA12878. Individual callsets can be imported, and a consensus algorithm is run over all callsets in the database to create a consensus collection, which can be used to assess NA12878 callsets for GATK and methods development
-- Framework for representing simple VariantContexts and Genotypes in MongoDB, querying for records, and iterating over them in the GATK
-- Not hooked up to Tribble, but could be done reasonably easily now (future TODO)
-- Tools to import callsets, create consensus callsets, import and export reviews
-- Scripts to reset the knowledge base and repopulate it with the standard data files (Eric will expand)
-- Actually scales to all of chr20, includes AssessNA12878 that reads a VCF and itemizes it against the truth data set
-- ImportCallset can load OMNI, HM3, CEU best practices, mills/devine sites and genotypes, properly marking sites as poly/mono/unk as well as TP/FP/UNK based on command line parameters
-- Added shell scripts that start up a local mongo db, that connect to a local or BI hosted mongo for NA12878.db for debugging, and a setupNA12878db script that can load OMNI, HM3, CEU best practices, Mills/Devine into the db and then update the consensus.
-- Reviewed sites can be exported to a VCF, and imported again, as a mechanism to safely store the only non-recoverable data from the Mongo DB.
-- Created a NA12878DBWalker that manages the outer DB interaction, and that all MongoDB interacting walkers inherit from. Added a NA12878DBArgumentCollection.java consolating all of the common command line arguments (though strictly not necessary as all of this occurs in the root walker)
UnitTests
-- Can connect to a test knowledge base for development and unit testing
-- PolymorphicStatus, TruthStatus, SiteIterator
-- NA12878KBUnitTestBase provides simple utilities for connecting to the test mongo db, getting calls, etc
-- MongoVariantContext tests creation, matching, and encoding -> writing -> read -> decoding from the mongodb
AssessNA12878
-- Generic tool for comparing a NA12878 callset against the knowledge base. See http://gatkforums.broadinstitute.org/discussion/1848/using-the-na12878-knowledge-base for detailed documentation
-- Performs trivial filtering on FS, MQ, QD for SNPs and non-SNPs to separate out variants likely to be filtered from those that are honest-to-goodness FPs
Misc
-- Ability to provide Description for Simplified GATK report
Joel Thibault
Ryan Poplin
Eric Banks
Mark DePristo
Menachem Fromer
Mauricio Carneiro
Guillermo del Angel