Easily visualize your direct-to-consumer genetics next to 2500+ samples from the 1000 genomes project. Evaluate the performance of a custom set of ancestry-informative snps (AISNPs) at classifying the genetic ancestry of the 1000 genomes samples using a machine learning model.
A subset of 1000 Genomes Project samples' single nucleotide polymorphism(s), or, SNP(s) have been parsed from the publicly available .bcf
files.
The subset of SNPs
, AISNPs (ancestry-informative snps), were chosen from two publications:
- Set of 55 AISNPs. Progress toward an efficient panel of SNPs for ancestry inference. Kidd et al. 2014
- Set of 128 AISNPs. Ancestry informative marker sets for determining continental origin and admixture proportions in common populations in America.. Kosoy et al. 2009 (Seldin Lab)
ezancestry ships with pretrained k-nearest neighbor models for all combinations of following:
* Kidd (55 AISNPs)
* Seldin (128 AISNPs)
* continental-level population (superpopulation)
* regional population (population)
* principal component analysis (PCA)
Install ezancestry with pip:
pip install ezancestry
Or clone the repository and run pip install
from the directory:
git clone git@github.com:arvkevi/ezancestry.git
cd ezancestry
pip install .
The first time ezancestry
is run it will generate a config.ini
file and data/
directory in your home directory under ${HOME}/.ezancestry
.
You can edit conf.ini
to change the default settings, but it is not necessary to use ezancestry. The settings are just a utility for the user so they don't have to be verbose when interacting with the software. The settings are also keyword arguments to each of the commands in the ezancestry API, so you can always override the default settings.
These will be created in your home directory:
${HOME}/.ezancestry/conf.ini
${HOME}/.ezancestry/data/
Explanations of each setting is described in the Options section of the --help
of each command, for example:
ezancestry predict --help
Usage: ezancestry predict [OPTIONS] INPUT_DATA
Predict ancestry from genetic data.
* Default arguments are from the ~/.ezancestry/conf.ini file. *
Arguments:
INPUT_DATA Can be a file path to raw genetic data (23andMe, ancestry.com,
.vcf) file, a path to a directory containing several raw genetic
files, or a (tab or comma) delimited file with sample ids as
rows and snps as columns. [required]
Options:
--output-directory TEXT The directory where to write the prediction
results file
--write-predictions / --no-write-predictions
If True, write the predictions to a file. If
False, return the predictions as a
dataframe. [default: True]
--models-directory TEXT The path to the directory where the model
files are located.
--aisnps-directory TEXT The path to the directory where the AISNPs
files are located.
--aisnps-set TEXT The name of the AISNP set to use. To start,
choose either 'Kidd' or 'Seldin'. The
default value in conf.ini is 'Kidd'. *If
using your AISNP set, this value will be the
in the namingc onvention for all the new
model files that are created*
--help Show this message and exit.
ezancestry can be used as a command-line tool or as a Python library.
ezancestry predict
comes with pre-trained models when --aisnps-set=kidd
or --aisnps-set=seldin
.`
There are four commands available:
fetch
: generate a csv file with all the 1000 Genome samples (rows) at the specified AISNPs locations (columns).predict
: predict the genetic ancestry of a sample or cohort of samples using the nearest neighbors model.plot
: plot the genetic ancestry of samples using the output ofpredict
.train
: build a k-nearest neighbors model from the 1000 genomes data using a custom set of AISNPs.
Use the commands in the following way:
ezancestry can predict the genetic ancestry of a sample or cohort of samples using the nearest neighbors model.
The input_data
can be a file path to raw genetic data (23andMe, ancestry.com, .vcf) file, a path to a directory containing several raw genetic files, or a (tab or comma) delimited file with sample ids as rows and snps as columns.
This writes a file, predictions.csv
to the output_directory
(defaults to current directory). This file contains predicted ancestry for each sample.
Direct-to-consumer genetic data file (23andMe, ancestry.com, etc.):
ezancestry predict mygenome.txt
Directory of direct-to-consumer genetic data files or .vcf files:
ezancestry predict /path/to/genetic_datafiles
comma-separated file with sample ids as rows and snps as columns, filled with genotypes as values
ezancestry predict ${HOME}/.ezancestry/data/aisnps/thousand_genomes.KIDD.dataframe.csv
Visualize the output of predict
using the plot
command. This will open a 3d scatter plot in a browser.
ezancestry plot predictions.csv
This command will download all of the data required to build a new nearest neighbors model for a custom set of AISNPs. If you want to use existing models, see predict
and plot
.
Without any arguments this command will download all necessary data to build new models and put it in the ${HOME}/.ezancestry/data/
directory.
ezancestry fetch
Now you are ready to build a new model with train
.
Test the discriminative power of your custom set of AISNPs.
This command will build all the necessary models to visualize and predict the 1000 genomes samples as well as user-uploaded samples. A model performace evaluation report will be generated for a five-fold cross-validation on the training set of the 1000 genomes samples as well as a report for the holdout set.
Create a custom AISNP file here: ~/.ezancestry/data/aisnps/custom.AISNP.txt
. The prefix of the filename, custom
, can be whatever you want. Note that this value is used as the aisnps-set
keyword argument for other ezancestry commands.
The file should look like this:
id chromosome position
rs731257 7 12669251
rs2946788 11 24010530
rs3793451 9 71659280
rs10236187 7 139447377
rs1569175 2 201021954
ezancestry train --aisnps-set=custom
See the notebook
Contributions are welcome! Please feel free to create an issue for discussion or make a pull request.