Inspect & standardize identifiers#

To make data queryable by an entity identifier, one needs to ensure that identifiers comply to a chosen standard.

Bionty enables this by mapping metadata on the versioned ontologies using inspect().

For terms that are not directly mappable, we offer (also see Search & lookup terms):

import bionty as bt
import pandas as pd

Inspect and mapping synonyms of gene identifiers#

To illustrate it, let us generate a DataFrame that stores a number of gene identifiers, some of which corrupted.

data = {
    "gene symbol": ["A1CF", "A1BG", "FANCD1", "corrupted"],
    "hgnc id": ["HGNC:24086", "HGNC:5", "HGNC:1101", "corrupted"],
    "ensembl_gene_id": [
        "ENSG00000148584",
        "ENSG00000121410",
        "ENSG00000188389",
        "ENSGcorrupted",
    ],
}
df_orig = pd.DataFrame(data).set_index("ensembl_gene_id")
df_orig
gene symbol hgnc id
ensembl_gene_id
ENSG00000148584 A1CF HGNC:24086
ENSG00000121410 A1BG HGNC:5
ENSG00000188389 FANCD1 HGNC:1101
ENSGcorrupted corrupted corrupted

First we can check whether any of our values are mappable against the ontology reference.

Tip: available fields are accessible via gene_bt.fields

gene_bt = bt.Gene()

gene_bt
Gene
Species: human
Source: ensembl, release-109
#terms: 75124

πŸ“– Gene.df(): ontology reference table
πŸ”Ž Gene.lookup(): autocompletion of terms
🎯 Gene.search(): free text search of terms
🧐 Gene.inspect(): check if identifiers are mappable
πŸ‘½ Gene.map_synonyms(): map synonyms to standardized names
βš– Gene.diff(): difference between two versions
πŸ”— Gene.ontology: Pronto.Ontology object
gene_bt.inspect(df_orig.index, gene_bt.ensembl_gene_id)
βœ… 3 terms (75.0%) are mapped
πŸ”Ά 1 terms (25.0%) are not mapped
{'mapped': ['ENSG00000148584', 'ENSG00000121410', 'ENSG00000188389'],
 'not_mapped': ['ENSGcorrupted']}

The same procedure is available for gene symbols. First, we inspect which symbols are mappable against the ontology.

gene_bt.inspect(df_orig["gene symbol"], gene_bt.symbol)
πŸ”Ά The identifiers contain synonyms!
   To increase mappability, standardize them via '.map_synonyms()'
βœ… 2 terms (50.0%) are mapped
πŸ”Ά 2 terms (50.0%) are not mapped
{'mapped': ['A1CF', 'A1BG'], 'not_mapped': ['FANCD1', 'corrupted']}

Apparently 2 of the gene symbols are mappable. Bionty further warns us that some of our symbols can be mapped into standardized symbols.

Mapping synonyms returns a list of standardized terms:

mapped_symbol_synonyms = gene_bt.map_synonyms(df_orig["gene symbol"])

mapped_symbol_synonyms
['A1CF', 'A1BG', 'BRCA2', 'corrupted']

Optionally, only returns a mapper of {synonym : standardized name}:

gene_bt.map_synonyms(df_orig["gene symbol"], return_mapper=True)
{'FANCD1': 'BRCA2'}

We can use the standardized symbols as the new index:

df_curated = df_orig.reset_index()
df_curated.index = mapped_symbol_synonyms
df_curated
ensembl_gene_id gene symbol hgnc id
A1CF ENSG00000148584 A1CF HGNC:24086
A1BG ENSG00000121410 A1BG HGNC:5
BRCA2 ENSG00000188389 FANCD1 HGNC:1101
corrupted ENSGcorrupted corrupted corrupted

You may return a DataFrame with a boolean column indicating if the identifiers are mappable:

gene_bt.inspect(df_curated.index, gene_bt.symbol, return_df=True)
βœ… 3 terms (75.0%) are mapped
πŸ”Ά 1 terms (25.0%) are not mapped
__mapped__
A1CF True
A1BG True
BRCA2 True
corrupted False

Standardize and look up unmapped CellMarker identifiers#

Depending on how the data was collected and which terminology was used, it is not always possible to curate values. Some values might have used a different standard or be corrupted.

This section will demonstrate how to look up unmatched terms and curate them using CellMarker.

First, we take an example DataFrame whose index containing a valid & invalid cell markers (antibody targets) and an additional feature (time) from a flow cytometry dataset.

markers = pd.DataFrame(
    index=[
        "KI67",
        "CCR7",
        "CD14",
        "CD8",
        "CD45RA",
        "CD4",
        "CD3",
        "CD127a",
        "PD1",
        "Invalid-1",
        "Invalid-2",
        "CD66b",
        "Siglec8",
        "Time",
    ]
)

Let’s instantiate the CellMarker ontology with the default database and version.

cellmarker_bt = bt.CellMarker()

cellmarker_bt


CellMarker
Species: human
Source: cellmarker, 2.0
#terms: 15466

πŸ“– CellMarker.df(): ontology reference table
πŸ”Ž CellMarker.lookup(): autocompletion of terms
🎯 CellMarker.search(): free text search of terms
🧐 CellMarker.inspect(): check if identifiers are mappable
πŸ‘½ CellMarker.map_synonyms(): map synonyms to standardized names
βš– CellMarker.diff(): difference between two versions
πŸ”— CellMarker.ontology: Pronto.Ontology object

Now let’s check which cell markers from the file can be found in the reference:

cellmarker_bt.inspect(markers.index, cellmarker_bt.name)
πŸ”Ά Detected inconsistent casing of mapped terms!
   For best practice, standardize casing via '.map_synonyms()'
βœ… 10 terms (71.4%) are mapped
πŸ”Ά 4 terms (28.6%) are not mapped
{'mapped': ['KI67',
  'CCR7',
  'CD14',
  'CD8',
  'CD45RA',
  'CD4',
  'CD3',
  'PD1',
  'CD66b',
  'Siglec8'],
 'not_mapped': ['CD127a', 'Invalid-1', 'Invalid-2', 'Time']}

Logging suggests we map synonyms:

synonyms_mapper = cellmarker_bt.map_synonyms(markers.index, return_mapper=True)

Now we mapped 2 additional terms:

synonyms_mapper
{'KI67': 'Ki67', 'CCR7': 'Ccr7', 'CD14': 'Cd14', 'CD4': 'Cd4'}

Let’s replace the synonyms with standardized names in the markers DataFrame:

markers.rename(index=synonyms_mapper, inplace=True)

From the logging, it can be seen that 4 terms were not found in the reference!

Among them Time, Invalid-1 and Invalid-2 are non-marker channels which won’t be curated by cell marker.

cellmarker_bt.inspect(markers.index, cellmarker_bt.name)
βœ… 10 terms (71.4%) are mapped
πŸ”Ά 4 terms (28.6%) are not mapped
{'mapped': ['Ki67',
  'Ccr7',
  'Cd14',
  'CD8',
  'CD45RA',
  'Cd4',
  'CD3',
  'PD1',
  'CD66b',
  'Siglec8'],
 'not_mapped': ['CD127a', 'Invalid-1', 'Invalid-2', 'Time']}

We don’t really find CD127a, let’s check in the lookup with auto-completion:

lookup = cellmarker_bt.lookup()
lookup.cd127
CellMarker(name='CD127', synonyms='', gene_symbol='IL7R', ncbi_gene_id='3575', uniprotkb_id='P16871', _5='cd127')

Indeed we find it should be cd127, we had a typo there with cd127a.

Now let’s fix the markers so all of them can be linked:

Tip

Using the .lookup instead of passing a string helps eliminate possible typos!

curated_df = markers.rename(index={"CD127a": lookup.cd127.name})

Optionally, run a fuzzy match:

cellmarker_bt.search("CD127a").head()
synonyms gene_symbol ncbi_gene_id uniprotkb_id __agg__ __ratio__
name
CD127 IL7R 3575 P16871 cd127 90.909091
CD167a None None None cd167a 83.333333
CD120a TNFRSF1A 7132 P19438 cd120a 83.333333
CD172a None None None cd172a 83.333333
CD107A LAMP1 3916 A0A024RDY3 cd107a 83.333333

OK, now we can try to run curate again and all cell markers are linked!

cellmarker_bt.inspect(curated_df.index, cellmarker_bt.name)
βœ… 11 terms (78.6%) are mapped
πŸ”Ά 3 terms (21.4%) are not mapped
{'mapped': ['Ki67',
  'Ccr7',
  'Cd14',
  'CD8',
  'CD45RA',
  'Cd4',
  'CD3',
  'CD127',
  'PD1',
  'CD66b',
  'Siglec8'],
 'not_mapped': ['Invalid-1', 'Invalid-2', 'Time']}