def annotate_snvs(adapter, vcf_obj):
"""Annotate all variants in a VCF
Args:
adapter(loqusdb.plugin.adapter)
vcf_obj(cyvcf2.VCF)
Yields:
variant(cyvcf2.Variant): Annotated variant
"""
variants = {}
for nr_variants, variant in enumerate(vcf_obj, 1):
# Add the variant to current batch
variants[get_variant_id(variant)] = variant
# If batch len == 1000 we annotate the batch
if (nr_variants % 1000) == 0:
for var_obj in adapter.search_variants(list(variants.keys())):
var_id = var_obj["_id"]
if var_id in variants:
annotate_variant(variants[var_id], var_obj)
for variant_id in variants:
yield variants[variant_id]
variants = {}
for var_obj in adapter.search_variants(list(variants.keys())):
var_id = var_obj["_id"]
if var_id in variants:
annotate_variant(variants[var_id], var_obj)
for variant_id in variants:
yield variants[variant_id]
def test_delete_variant(real_mongo_adapter, het_variant, case_obj):
## GIVEN a database with one variant that is observed twice
db = real_mongo_adapter.db
case_id = case_obj["case_id"]
db.variant.insert_one({
"_id": get_variant_id(het_variant),
"families": [case_id, "2"],
"observations": 2,
})
mongo_variant = db.variant.find_one()
assert mongo_variant["observations"] == 2
## WHEN deleting the variant for one case
delete_variants(
adapter=real_mongo_adapter,
vcf_obj=[het_variant],
case_obj=case_obj,
case_id="2",
)
mongo_variant = db.variant.find_one()
## THEN assert that one case has been removed from 'families'
assert mongo_variant["families"] == [case_id]
## THEN assert that the observation count is decreased
assert mongo_variant["observations"] == 1
def test_delete_variant(real_mongo_adapter, het_variant, case_obj):
## GIVEN a database with one variant that is observed twice
db = real_mongo_adapter.db
case_id = case_obj['case_id']
db.variant.insert_one({
'_id': get_variant_id(het_variant),
'families': [case_id, '2'],
'observations': 2,
})
mongo_variant = db.variant.find_one()
assert mongo_variant['observations'] == 2
## WHEN deleting the variant for one case
delete_variants(
adapter=real_mongo_adapter,
vcf_obj=[het_variant],
case_obj=case_obj,
case_id='2',
)
mongo_variant = db.variant.find_one()
## THEN assert that one case has been removed from 'families'
assert mongo_variant['families'] == [case_id]
## THEN assert that the observation count is decreased
assert mongo_variant['observations'] == 1
def build_profile_variant(variant):
"""Returns a ProfileVariant object
Args:
variant (cyvcf2.Variant)
Returns:
variant (models.ProfileVariant)
"""
chrom = variant.CHROM
if chrom.startswith(("chr", "CHR", "Chr")):
chrom = chrom[3:]
pos = int(variant.POS)
variant_id = get_variant_id(variant)
ref = variant.REF
alt = variant.ALT[0]
maf = get_maf(variant)
profile_variant = ProfileVariant(
variant_id=variant_id, chrom=chrom, pos=pos, ref=ref, alt=alt, maf=maf, id_column=variant.ID
)
return profile_variant
def insert_sv_variants(adapter: MongoAdapter, case_obj: Case) -> None:
"""Build sv_variant documents and insert them into database on the fly, one at a time"""
for variant in VCF(case_obj.vcf_sv_path, threads=settings.cyvcf_threads):
variant_id = get_variant_id(variant=variant)
ref = variant.REF
alt = variant.ALT[0]
coordinates = get_coords(variant)
chrom = coordinates["chrom"]
pos = coordinates["pos"]
variant_obj = Variant(
variant_id=variant_id,
chrom=chrom,
pos=pos,
end=coordinates["end"],
ref=ref,
alt=alt,
end_chrom=coordinates["end_chrom"],
sv_type=coordinates["sv_type"],
sv_len=coordinates["sv_length"],
case_id=case_obj.case_id,
homozygote=0,
hemizygote=0,
is_sv=True,
id_column=variant.ID,
)
adapter.add_structural_variant(variant=variant_obj, max_window=settings.load_sv_window)
def get_profiles(adapter: MongoAdapter, vcf_file: str) -> Dict[str, str]:
"""
Reads VCF file containing one or more samples.
Creates a dictionary where each sample ID from VCF file is a key.
Retrieves coordinates for each variant from loqusdb.profile_variants
Adds each variant of each sample as value of the dictionary.
Returns a dictionary :
{SAMPLE_ID : [var1, var2, ..., var50]}
"""
vcf = VCF(vcf_file, threads=settings.cyvcf_threads)
individuals = vcf.samples
profiles = {individual: [] for individual in individuals}
for profile_variant in adapter.profile_variants():
ref = profile_variant["ref"]
alt = profile_variant["alt"]
pos = profile_variant["pos"]
end = pos + 1
chrom = profile_variant["chrom"]
region = f"{chrom}:{pos}-{end}"
# Find variants in region
found_variant = False
for variant in vcf(region):
variant_id = get_variant_id(variant)
# If variant id i.e. chrom_pos_ref_alt matches
if variant_id == profile_variant["_id"]:
found_variant = True
# find genotype for each individual in vcf
for i, individual in enumerate(individuals):
genotype = GENOTYPE_MAP[variant.gt_types[i]]
if genotype == "hom_alt":
gt_str = f"{alt}{alt}"
elif genotype == "het":
gt_str = f"{ref}{alt}"
else:
gt_str = f"{ref}{ref}"
# Append genotype to profile string of individual
profiles[individual].append(gt_str)
# Break loop if variant is found in region
break
# If no call was found for variant, give all samples a hom ref genotype
if not found_variant:
for individual in individuals:
profiles[individual].append(f"{ref}{ref}")
return profiles
def annotate_snv(adpter, variant):
"""Annotate an SNV/INDEL variant
Args:
adapter(loqusdb.plugin.adapter)
variant(cyvcf2.Variant)
"""
variant_id = get_variant_id(variant)
variant_obj = adapter.get_variant(variant={"_id": variant_id})
annotated_variant = annotated_variant(variant, variant_obj)
return annotated_variant
def insert_snv_variants(adapter: MongoAdapter, case_obj: Case) -> None:
"""Build variant documents and bulk insert them into database"""
variants = []
for variant in VCF(case_obj.vcf_path, threads=settings.cyvcf_threads):
variant_id = get_variant_id(variant=variant)
ref = variant.REF
alt = variant.ALT[0]
coordinates = get_coords(variant)
chrom = coordinates["chrom"]
pos = coordinates["pos"]
found_homozygote = 0
found_hemizygote = 0
for ind_obj in case_obj.individuals:
ind_pos = ind_obj["ind_index"]
if int(variant.gt_quals[ind_pos]) < settings.load_gq_threshold:
continue
genotype = GENOTYPE_MAP[variant.gt_types[ind_pos]]
if genotype not in ["het", "hom_alt"]:
continue
if genotype == "hom_alt":
found_homozygote = 1
if (
chrom in ["X", "Y"]
and ind_obj["sex"] == 1
and not check_par(chrom, pos, genome_build=settings.genome_build)
):
found_hemizygote = 1
variant_obj = Variant(
variant_id=variant_id,
chrom=chrom,
pos=pos,
end=coordinates["end"],
ref=ref,
alt=alt,
end_chrom=coordinates["end_chrom"],
sv_type=coordinates["sv_type"],
sv_len=coordinates["sv_length"],
case_id=case_obj.case_id,
homozygote=found_homozygote,
hemizygote=found_hemizygote,
is_sv=False,
id_column=variant.ID,
)
variants.append(variant_obj)
adapter.add_variants(variants=variants)
def test_delete_variants(real_mongo_adapter, het_variant, case_obj):
## GIVEN a database with one variant
db = real_mongo_adapter.db
case_id = case_obj["case_id"]
db.variant.insert_one({
"_id": get_variant_id(het_variant),
"families": [case_id],
"observations": 1,
})
mongo_variant = db.variant.find_one()
assert mongo_variant["families"] == [case_id]
## WHEN deleting the variant
delete_variants(adapter=real_mongo_adapter,
vcf_obj=[het_variant],
case_obj=case_obj)
mongo_variant = db.variant.find_one()
## THEN assert that the variant was not found
assert mongo_variant is None
def test_delete_variants(real_mongo_adapter, het_variant, case_obj):
## GIVEN a database with one variant
db = real_mongo_adapter.db
case_id = case_obj['case_id']
db.variant.insert_one({
'_id': get_variant_id(het_variant),
'families': [case_id],
'observations': 1,
})
mongo_variant = db.variant.find_one()
assert mongo_variant['families'] == [case_id]
## WHEN deleting the variant
delete_variants(adapter=real_mongo_adapter,
vcf_obj=[het_variant],
case_obj=case_obj)
mongo_variant = db.variant.find_one()
## THEN assert that the variant was not found
assert mongo_variant == None
def get_profiles(adapter, vcf_file):
"""Given a vcf, get a profile string for each sample in the vcf
based on the profile variants in the database
Args:
adapter(MongoAdapter): Adapter to mongodb
vcf_file(str): Path to vcf file
Returns:
profiles (dict(str)): The profiles (given as strings) for each sample
in vcf.
"""
vcf = get_file_handle(vcf_file)
individuals = vcf.samples
profiles = {individual: [] for individual in individuals}
for profile_variant in adapter.profile_variants():
ref = profile_variant["ref"]
alt = profile_variant["alt"]
pos = profile_variant["pos"]
end = pos + 1
chrom = profile_variant["chrom"]
region = f"{chrom}:{pos}-{end}"
# Find variants in region
found_variant = False
for variant in vcf(region):
variant_id = get_variant_id(variant)
# If variant id i.e. chrom_pos_ref_alt matches
if variant_id == profile_variant["_id"]:
found_variant = True
# find genotype for each individual in vcf
for i, individual in enumerate(individuals):
genotype = GENOTYPE_MAP[variant.gt_types[i]]
if genotype == "hom_alt":
gt_str = f"{alt}{alt}"
elif genotype == "het":
gt_str = f"{ref}{alt}"
else:
gt_str = f"{ref}{ref}"
# Append genotype to profile string of individual
profiles[individual].append(gt_str)
# Break loop if variant is found in region
break
# If no call was found for variant, give all samples a hom ref genotype
if not found_variant:
for individual in individuals:
profiles[individual].append(f"{ref}{ref}")
return profiles
def check_vcf(vcf_path, expected_type="snv"):
"""Check if there are any problems with the vcf file
Args:
vcf_path(str)
expected_type(str): 'sv' or 'snv'
Returns:
vcf_info(dict): dict like
{
'nr_variants':<INT>,
'variant_type': <STR> in ['snv', 'sv'],
'individuals': <LIST> individual positions in file
}
"""
LOG.info("Check if vcf is on correct format...")
vcf = VCF(vcf_path)
individuals = vcf.samples
variant_type = None
previous_pos = None
previous_chrom = None
posititon_variants = set()
nr_variants = 0
for nr_variants, variant in enumerate(vcf, 1):
# Check the type of variant
current_type = "sv" if variant.var_type == "sv" else "snv"
if not variant_type:
variant_type = current_type
# Vcf can not include both snvs and svs
if variant_type != current_type:
raise VcfError("Vcf includes a mix of snvs and svs")
current_chrom = variant.CHROM
current_pos = variant.POS
# We start with a simple id that can be used by SV:s
variant_id = "{0}_{1}".format(current_chrom, current_pos)
# For SNVs we can create a proper variant id with chrom_pos_ref_alt
if variant_type == "snv":
variant_id = get_variant_id(variant)
# Initiate variables
if not previous_chrom:
previous_chrom = current_chrom
previous_pos = current_pos
posititon_variants = {variant_id}
continue
# Update variables if new chromosome
if current_chrom != previous_chrom:
previous_chrom = current_chrom
previous_pos = current_pos
posititon_variants = {variant_id}
continue
if variant_type == "snv":
# Check if variant is unique
if current_pos == previous_pos:
if variant_id in posititon_variants:
raise VcfError("Variant {0} occurs several times" " in vcf".format(variant_id))
else:
posititon_variants.add(variant_id)
# Check if vcf is sorted
else:
if not current_pos >= previous_pos:
raise VcfError("Vcf if not sorted in a correct way")
previous_pos = current_pos
# Reset posititon_variants since we are on a new position
posititon_variants = {variant_id}
if variant_type != expected_type:
raise VcfError(
"VCF file does not only include {0}s, please check vcf {1}".format(
expected_type.upper(), vcf_path
)
)
LOG.info("Vcf file %s looks fine", vcf_path)
LOG.info("Nr of variants in vcf: {0}".format(nr_variants))
LOG.info("Type of variants in vcf: {0}".format(variant_type))
return {
"nr_variants": nr_variants,
"variant_type": variant_type,
"individuals": individuals,
}
