/** Tests to ensure that a locus is bi-allelic within the given set of samples. */
private boolean isVariant(final Genotype... gts) {
for (final Genotype gt : gts) {
if (gt.isCalled() && !gt.isHomRef()) return true;
}
return false;
}
private int getGT(Genotype gt) {
if (gt.isHomRef()) {
return 0;
} else if (gt.isHet()) {
return 1;
} else {
return 2;
}
}
/**
* Provides the next record from the underlying iterator after applying filter strings generated
* by the set of filters in use by the iterator.
*/
@Override
public VariantContext next() {
final VariantContext ctx = this.iterator.next();
final Set<String> filterStrings = new HashSet<String>();
// Collect variant level filters
for (final VariantFilter filter : this.filters) {
final String val = filter.filter(ctx);
if (val != null) filterStrings.add(val);
}
// Collect genotype level filters in a Map of Sample -> List<filter string>
final ListMap<String, String> gtFilterStrings = new ListMap<String, String>();
final Set<String> variantSamples = new HashSet<String>();
for (final Genotype gt : ctx.getGenotypes()) {
if (gt.isCalled() && !gt.isHomRef()) variantSamples.add(gt.getSampleName());
for (final GenotypeFilter filter : gtFilters) {
final String filterString = filter.filter(ctx, gt);
if (filterString != null) gtFilterStrings.add(gt.getSampleName(), filterString);
}
}
// If all genotypes are filtered apply a site level filter
if (gtFilterStrings.keySet().containsAll(variantSamples)) {
filterStrings.add(ALL_GTS_FILTERED);
}
// Make a builder and set the site level filter appropriately
final VariantContextBuilder builder = new VariantContextBuilder(ctx);
if (filterStrings.isEmpty()) {
builder.passFilters();
} else {
builder.filters(filterStrings);
}
// Apply filters to the necessary genotypes
builder.noGenotypes();
final List<Genotype> newGenotypes = new ArrayList<Genotype>(ctx.getNSamples());
for (final Genotype gt : ctx.getGenotypes()) {
final GenotypeBuilder gtBuilder = new GenotypeBuilder(gt);
final List<String> filtersLocal = gtFilterStrings.get(gt.getSampleName());
if (filtersLocal == null || filtersLocal.isEmpty()) {
gtBuilder.filter(PASS_FILTER);
} else {
gtBuilder.filters(filtersLocal);
}
newGenotypes.add(gtBuilder.make());
}
builder.genotypes(newGenotypes);
return builder.make();
}
@Override
public Map<String, Object> annotate(
final RefMetaDataTracker tracker,
final AnnotatorCompatible walker,
final ReferenceContext ref,
final Map<String, AlignmentContext> stratifiedContexts,
final VariantContext vc,
final Map<String, PerReadAlleleLikelihoodMap> stratifiedPerReadAlleleLikelihoodMap) {
final GenotypesContext genotypes = vc.getGenotypes();
if (genotypes == null || genotypes.size() < MIN_SAMPLES) {
if (!warningLogged) {
logger.warn("Too few genotypes");
warningLogged = true;
}
return null;
}
int refCount = 0;
int hetCount = 0;
int homCount = 0;
for (final Genotype g : genotypes) {
if (g.isNoCall()) continue;
// TODO - fix me:
// Right now we just ignore genotypes that are not confident, but this throws off
// our HW ratios. More analysis is needed to determine the right thing to do when
// the genotyper cannot decide whether a given sample is het or hom var.
if (g.getLog10PError() > MIN_LOG10_PERROR) continue;
if (g.isHomRef()) refCount++;
else if (g.isHet()) hetCount++;
else homCount++;
}
if (refCount + hetCount + homCount == 0) return null;
double pvalue = HardyWeinbergCalculation.hwCalculate(refCount, hetCount, homCount);
// System.out.println(refCount + " " + hetCount + " " + homCount + " " + pvalue);
Map<String, Object> map = new HashMap<>();
map.put(getKeyNames().get(0), String.format("%.1f", QualityUtils.phredScaleErrorRate(pvalue)));
return map;
}
@Override
public void accumulate(final VariantContext ctx) {
logger.record(ctx.getContig(), ctx.getStart());
final String variantChrom = ctx.getContig();
final int variantPos = ctx.getStart();
// Skip anything a little too funky
if (ctx.isFiltered()) return;
if (!ctx.isVariant()) return;
if (SKIP_CHROMS.contains(variantChrom)) return;
for (final MendelianViolationMetrics trio : trios) {
final Genotype momGt = ctx.getGenotype(trio.MOTHER);
final Genotype dadGt = ctx.getGenotype(trio.FATHER);
final Genotype kidGt = ctx.getGenotype(trio.OFFSPRING);
// if any genotype:
// - has a non-snp allele; or
// - lacks a reference allele
//
// then ignore this trio
if (CollectionUtil.makeList(momGt, dadGt, kidGt)
.stream()
.anyMatch(
gt ->
gt.isHetNonRef()
|| Stream.concat(Stream.of(ctx.getReference()), gt.getAlleles().stream())
.anyMatch(a -> a.length() != 1 || a.isSymbolic()))) {
continue;
}
// if between the trio there are more than 2 alleles including the reference, continue
if (Stream.concat(
Collections.singleton(ctx.getReference()).stream(),
CollectionUtil.makeList(momGt, dadGt, kidGt)
.stream()
.flatMap(gt -> gt.getAlleles().stream()))
.collect(Collectors.toSet())
.size()
> 2) continue;
// Test to make sure:
// 1) That the site is in fact variant in the trio
// 2) that the offspring doesn't have a really wacky het allele balance
if (!isVariant(momGt, dadGt, kidGt)) continue;
if (kidGt.isHet()) {
final int[] ad = kidGt.getAD();
if (ad == null) continue;
final List<Integer> adOfAlleles =
kidGt
.getAlleles()
.stream()
.map(a -> ad[ctx.getAlleleIndex(a)])
.collect(Collectors.toList());
final double minAlleleFraction =
Math.min(adOfAlleles.get(0), adOfAlleles.get(1))
/ (double) (adOfAlleles.get(0) + adOfAlleles.get(1));
if (minAlleleFraction < MIN_HET_FRACTION) continue;
}
///////////////////////////////////////////////////////////////
// Determine whether the offspring should be haploid at this
// locus and which is the parental donor of the haploid genotype
///////////////////////////////////////////////////////////////
boolean haploid = false;
Genotype haploidParentalGenotype = null;
if (FEMALE_CHROMS.contains(variantChrom) && trio.OFFSPRING_SEX != Sex.Unknown) {
if (trio.OFFSPRING_SEX == Sex.Female) {
// famale
haploid = false;
} else if (isInPseudoAutosomalRegion(variantChrom, variantPos)) {
// male but in PAR on X, so diploid
haploid = false;
} else {
// male, out of PAR on X, haploid
haploid = true;
haploidParentalGenotype = momGt;
}
}
// the PAR on the male chromosome should be masked so that reads
// align to the female chromosomes instead, so there's no point
// of worrying about that here.
if (MALE_CHROMS.contains(variantChrom)) {
if (trio.OFFSPRING_SEX == Sex.Male) {
haploid = true;
haploidParentalGenotype = dadGt;
} else {
continue;
}
}
// We only want to look at sites where we have high enough confidence that the genotypes we
// are looking at are
// interesting. We want to ensure that parents are always GQ>=MIN_GQ, and that the kid is
// either GQ>=MIN_GQ or in the
// case where kid is het that the phred-scaled-likelihood of being reference is >=MIN_GQ.
if (haploid
&& (haploidParentalGenotype.isNoCall() || haploidParentalGenotype.getGQ() < MIN_GQ))
continue;
if (!haploid
&& (momGt.isNoCall()
|| momGt.getGQ() < MIN_GQ
|| dadGt.isNoCall()
|| dadGt.getGQ() < MIN_GQ)) continue;
if (kidGt.isNoCall()) continue;
if (momGt.isHomRef() && dadGt.isHomRef() && !kidGt.isHomRef()) {
if (kidGt.getPL()[0] < MIN_GQ) continue;
} else if (kidGt.getGQ() < MIN_GQ) continue;
// Also filter on the DP for each of the samples - it's possible to miss hets when DP is too
// low
if (haploid && (kidGt.getDP() < MIN_DP || haploidParentalGenotype.getDP() < MIN_DP)) continue;
if (!haploid && (kidGt.getDP() < MIN_DP || momGt.getDP() < MIN_DP || dadGt.getDP() < MIN_DP))
continue;
trio.NUM_VARIANT_SITES++;
///////////////////////////////////////////////////////////////
// First test for haploid violations
///////////////////////////////////////////////////////////////
MendelianViolation type = null;
if (haploid) {
if (kidGt.isHet()) continue; // Should not see heterozygous calls at haploid regions
if (!haploidParentalGenotype.getAlleles().contains(kidGt.getAllele(0))) {
if (kidGt.isHomRef()) {
type = MendelianViolation.Haploid_Other;
trio.NUM_HAPLOID_OTHER++;
} else {
type = MendelianViolation.Haploid_Denovo;
trio.NUM_HAPLOID_DENOVO++;
}
}
}
///////////////////////////////////////////////////////////////
// Then test for diploid mendelian violations
///////////////////////////////////////////////////////////////
else if (isMendelianViolation(momGt, dadGt, kidGt)) {
if (momGt.isHomRef() && dadGt.isHomRef() && !kidGt.isHomRef()) {
trio.NUM_DIPLOID_DENOVO++;
type = MendelianViolation.Diploid_Denovo;
} else if (momGt.isHomVar() && dadGt.isHomVar() && kidGt.isHet()) {
trio.NUM_HOMVAR_HOMVAR_HET++;
type = MendelianViolation.HomVar_HomVar_Het;
} else if (kidGt.isHom()
&& ((momGt.isHomRef() && dadGt.isHomVar()) || (momGt.isHomVar() && dadGt.isHomRef()))) {
trio.NUM_HOMREF_HOMVAR_HOM++;
type = MendelianViolation.HomRef_HomVar_Hom;
} else if (kidGt.isHom()
&& ((momGt.isHom() && dadGt.isHet()) || (momGt.isHet() && dadGt.isHom()))) {
trio.NUM_HOM_HET_HOM++;
type = MendelianViolation.Hom_Het_Hom;
} else {
trio.NUM_OTHER++;
type = MendelianViolation.Other;
}
}
// Output a record into the family's violation VCF
if (type != null) {
// Create a new Context subsetted to the three samples
final VariantContextBuilder builder = new VariantContextBuilder(ctx);
builder.genotypes(
ctx.getGenotypes()
.subsetToSamples(CollectionUtil.makeSet(trio.MOTHER, trio.FATHER, trio.OFFSPRING)));
builder.attribute(MENDELIAN_VIOLATION_KEY, type.name());
// Copy over some useful attributes from the full context
if (ctx.hasAttribute(VCFConstants.ALLELE_COUNT_KEY))
builder.attribute(ORIGINAL_AC, ctx.getAttribute(VCFConstants.ALLELE_COUNT_KEY));
if (ctx.hasAttribute(VCFConstants.ALLELE_FREQUENCY_KEY))
builder.attribute(ORIGINAL_AF, ctx.getAttribute(VCFConstants.ALLELE_FREQUENCY_KEY));
if (ctx.hasAttribute(VCFConstants.ALLELE_NUMBER_KEY))
builder.attribute(ORIGINAL_AN, ctx.getAttribute(VCFConstants.ALLELE_NUMBER_KEY));
// Write out the variant record
familyToViolations.get(trio.FAMILY_ID).add(builder.make());
}
}
}
