phenopy

phenopy is a Python package to perform phenotype similarity scoring by semantic similarity. phenopy is a lightweight but highly optimized command line tool and library to efficiently perform semantic similarity scoring on generic entities with phenotype annotations from the Human Phenotype Ontology (HPO).

Installation

Install using pip:

pip install phenopy

Install from GitHub:

git clone https://github.com/GeneDx/phenopy.git
cd phenopy
python setup.py install

Command Line Usage

Initial setup

phenopy is designed to run with minimal setup from the user, to run phenopy with default parameters (recommended), skip ahead to the Commands overview.

This section provides details about where phenopy stores data resources and config files. The following occurs when you run phenopy for the first time.

1. phenopy creates a .phenopy/ directory in your home folder and downloads external resources from HPO into the $HOME/.phenopy/data/ directory.
2. phenopy creates a $HOME/.phenopy/phenopy.ini config file where users can set variables for phenopy to use at runtime.

Commands overview

phenopy is primarily used as a command line tool. An entity, as described here, is presented as a sample, gene, or disease, but could be any concept that warrants annotation of phenotype terms.

Use phenopy score to perform semantic similarity scoring in various formats. Write the results of any command to file using --output-file=/path/to/output_file.txt

1. Score similarity of entities defined by the HPO terms from an input file against all the OMIM diseases in .phenopy/data/phenotype.hpoa. We provide a test input file in the repo. The default summarization method is to use --summarization-method=BMWA which weighs each diseases' phenotypes by the frequency of a phenotype seen in each particular disease.

   phenopy score tests/data/test.score.txt  

   Output:

   #query	entity_id	score
   118200  210100  0.0
   118200  615779  0.0
   118200  613266  0.0052
   ...
   

2. Score similarity of entities defined by the HPO terms from an input file against all the OMIM diseases in .phenopy/data/phenotype.hpoa, to use the non-weighted summarization method use --summarization-method=BMA which uses a traditional best-match average summarization of semantic similarity scores when comparing terms from record a with terms from record b.

   phenopy score tests/data/test.score.txt --summarization-method=BMWA

   Output:

   #query	entity_id	score
   118200  210100  0.0
   118200  615779  0.0
   118200  613266  0.0052
   ...
   

3. Score similarity of an entities defined by the HPO terms from an input file against a custom list of entities with HPO annotations, referred to as the --records-file. Both files are in the same format.

   phenopy score tests/data/test.score-short.txt --records-file tests/data/test.score-long.txt

   Output:

   #query  entity_id       score
   118200  118200  0.0169
   118200  300905  0.0156
   118200  601098  0.0171
   ...
   

4. Score pairwise similarity of entities defined by the HPO terms from an input file using --self.

   phenopy score tests/data/test.score-long.txt --threads 4 --self

   Output:

   #query  entity_id       score
   118200  118200  0.2284
   118200  118210  0.1302
   118200  118211  0.1302
   118210  118210  0.2048
   118210  118211  0.2048
   118211  118211  0.2048
   

5. Score age-adjusted pairwise similarity of entities defined in the input file, using phenotype mean age and standard deviation defined in the --pheno_ages_file, select best-match weighted average as the scoring summarization method --summarization-method BMWA.

   phenopy score tests/data/test.score-short.txt --ages_distribution_file tests/data/phenotype_age.tsv --summarization-method BMWA --threads 4 --self

   Output:

   #query  entity_id       score
   118200  210100  0.0
   118200  177650  0.0127
   118200  241520  0.0
   ...
   

   The phenotype age file contains hpo-id, mean, sd as tab separated text as follows

   HP:0001251	6.0	3.0
   HP:0001263	1.0	1.0
   HP:0001290	1.0	1.0
   HP:0004322	10.0	3.0
   HP:0001249	6.0	3.0

If no phenotype ages file is provided --summarization-method=BMWA can be selected to use default, open access literature-derived phenotype ages (~ 1,400 age weighted phenotypes).

 phenopy score tests/data/test.score-short.txt  --summarization-method BMWA --threads 4

Parameters

For a full list of command arguments use phenopy [subcommand] --help:

phenopy score --help

Output:

    --output_file=OUTPUT_FILE
        File path where to store the results. [default: - (stdout)]
    --records_file=RECORDS_FILE
        An entity-to-phenotype annotation file in the same format as "input_file". This file, if provided, is used to score entries in the "input_file" against entries here. [default: None]
    --annotations_file=ANNOTATIONS_FILE
        An entity-to-phenotype annotation file in the same format as "input_file". This file, if provided, is used to add information content to the network. [default: None]
    --ages_distribution_file=AGES_DISTRIBUTION_FILE
        Phenotypes age summary stats file containing phenotype HPO id, mean_age, and std. [default: None]
    --self=SELF
        Score entries in the "input_file" against itself.
    --summarization_method=SUMMARIZATION_METHOD
        The method used to summarize the HRSS matrix. Supported Values are best match average (BMA), best match weighted average (BMWA), and maximum (maximum). [default: BMWA]
    --threads=THREADS
        Number of parallel processes to use. [default: 1]

Library Usage

The phenopy library can be used as a Python module, allowing more control for advanced users.

import os
from phenopy import generate_annotated_hpo_network
from phenopy.score import Scorer

# data directory
phenopy_data_directory = os.path.join(os.getenv('HOME'), '.phenopy/data')

# files used in building the annotated HPO network
obo_file = os.path.join(phenopy_data_directory, 'hp.obo')
disease_to_phenotype_file = os.path.join(phenopy_data_directory, 'phenotype.hpoa')

# if you have a custom ages_distribution_file, you can set it here.
ages_distribution_file = os.path.join(phenopy_data_directory, 'xa_age_stats_oct052019.tsv')

hpo_network, alt2prim, disease_records = \
    generate_annotated_hpo_network(obo_file,
                                   disease_to_phenotype_file,
                                   ages_distribution_file=ages_distribution_file
                                   )

scorer = Scorer(hpo_network)

terms_a = ['HP:0001882', 'HP:0011839']
terms_b = ['HP:0001263', 'HP:0000252']

print(scorer.score(terms_a, terms_b))

Output:

0.0005

The library can be used to prune parent phenotypes from the phenotype.hpoa and store pruned annotations as a file.

from phenopy.util import export_phenotype_hpoa_with_no_parents
# saves a new file of phenotype disease annotations with parent HPO terms removed from phenotype lists.
disease_to_phenotype_no_parents_file = os.path.join(phenopy_data_directory, 'phenotype.noparents.hpoa') 
export_phenotype_hpoa_with_no_parents(disease_to_phenotype_file, disease_to_phenotype_no_parents_file, hpo_network)

Config

While we recommend using the default settings for most users, the config file can be modified: $HOME/.phenopy/phenopy.ini.

To run phenopy with a different version of hp.obo, set the path of obo_file in $HOME/.phenopy/phenopy.ini.

Contributing

We welcome contributions from the community. Please follow these steps to setup a local development environment.

pipenv install --dev

To run tests locally:

pipenv shell
coverage run --source=. -m unittest discover --start-directory tests/
coverage report -m

References

The underlying algorithm which determines the semantic similarity for any two HPO terms is based on an implementation of HRSS, published here.