mantis-ml

• Introduction
• Installation
• Run
  • mantisml
  • mantisml-profiler
  • mantisml-overlap

Introduction

mantis-ml is a disease-agnostic gene prioritisation framework, implementing stochastic semi-supervised learning on top of scikit-learn and keras/tensorflow.
mantis-ml takes its name from the Greek word 'μάντης' which means 'fortune teller', 'predicter'.

Publication - Please cite:
Mantis-ml: Disease-Agnostic Gene Prioritization from High-Throughput Genomic Screens by Stochastic Semi-supervised Learning.
Dimitrios Vitsios, Slavé Petrovski.
The American Journal of Human Genetics (Cell Press), May 7, 2020 https://doi.org/10.1016/j.ajhg.2020.03.012

Gene prioritisation Atlas:
https://dvitsios.github.io/mantis-ml-predictions
This resource contains gene prediction results extracted by mantis-ml across 10 disease areas in 6 specialties: Cardiology, Immunology, Nephrology, Neurology, Psychiatry and Pulmonology.

Installation

Requirements: Python3 (tested with v3.6.7)

mantis-ml can be installed through pip:

pip install mantis-ml

Alternatively, it can be installed from the github repository:

git clone https://github.com/astrazeneca-cgr-publications/mantis-ml-release.git
pip install -e .

# or
python setup.py install

---

In either case, it is highly recommended to create a new virtual environment (e.g. with conda) before installing mantis-ml:

conda create -n mantis_ml python=3.6
conda config --append channels conda-forge   	# add conda-forge in the channels list
conda activate mantis_ml			# activate the newly created conda environment

---

You may now call the following scripts from the command line:

• mantisml: run mantis-ml gene prioritisation based on a provided config file (.yaml)
• mantisml-preview: preview selected phenotypes and features based on a provided config file
• mantisml-overlap: run enrichment test between mantis-ml predictions and an external ranked gene list to get refined gene predictions

Run each command with -h to see all available options.

Run

You need to provide a config file (.yaml) containing information about the diseases/phenotypes of interest.

Required field:

• Disease/Phenotype terms: terms that characterise a phenotype or disease of interest (free text)

Optional fields:

• Additional associated terms: terms used along with Disease/Phenotype terms to extract additional disease/phenotype-associated features (free text)
• Diseases/Phenotypes to exclude: terms to exclude from disease/phenotype characterisation and feature selection (free text)

Config examples:

# Epilepsy_config.yaml
Disease/Phenotype terms: epileptic, epilepsy, seizure
Additional associated terms: brain, nerve, nervous, neuronal, cerebellum, cerebral, hippocampus, hypothalamus
Diseases/Phenotypes to exclude: 

# CKD_config.yaml
Disease/Phenotype terms: renal, kidney, nephro, glomerul, distal tubule 
Additional associated terms: 
Diseases/Phenotypes to exclude: adrenal

Other example config files can be found under example-input or mantis-ml/conf.

Supervised learning models

• mantis-ml runs 6 different supervised models by default: Extra Trees, Random Forest, SVC, Gradient Boosting, XGBoost and Deep Neural Net.
• It is also possible to run mantis-ml with the -f / --fast option, which will force mantis-ml to train only 4 classifiers: Extra Trees, Random Forest, SVC and Gradient Boosting.
• Additionally, the user may explicitly specify which supervised models to be used for training via the -m option. The available model options are coded as follows:
  • et: Extra Trees
  • rf: Random Forest
  • gb: Gradient Boosting
  • xgb: XGBoost
  • svc: Support Vector Classifier
  • dnn: Deep Neural Net
  • stack: Stacking classifier

Multiple models may be specified using a , separator, e.g. -m et, -m et,stack,gb etc.

Estimated run time

mantis-ml total run time is inversely proportional to the number of known disease-associated (seed) genes (the fewer the seed genes are the more balanced datasets there are to be trained).
Example run times for different numbers of seed genes are given in this table. All results correspond to mantis-ml runs across 10 stochastic iterations, training with 6 different supervised models and using 10 cores.

Disease example	Num. of seed genes	Total run time
Epilepsy	864	2h
Chronic Kidney Disease	587	2.5h
Amyotrophic Lateral Sclerosis	77	11h

Representative examples of run times when using the -f / --fast option, two classifiers with the -m option or just the Stacking classifer are also given below (CKD dataset, 10 stochastic iterations, 10 cores):

Number of models	Total run time
6 (default)	2.5h
4 (-f)	43m
2 (-m et,rf)	19m
Stacking (-m stack)	1.5h

mantisml

You need to provide a config file (.yaml) and an output directory.
You may also:

• define the number of threads to use (-n option; default value: 4).
• define the number of stochastic iterations (-i option; default value: 10)
• provide a file with custom seed genes (-k option; file should contain new-line separated HGNC names; bypasses HPO)

mantisml -c [config_file] -o [output_dir] [-n nthreads] [-i iterations] [-k custom_seed_genes.txt]

Example

mantisml -c CKD_config.yaml -o ./CKD-run
mantisml -c Epilepsy_config.yaml -o /tmp/Epilepsy-testing -n 20

mantisml Output

mantisml predictions for all genes and across all classifiers can be found at [output_dir]/Gene-Predictions.
The AUC_performance_by_Classifier.pdf file under the same dir contains information about the AUC performance per classifier and thus informs about the best performing classifier.

Output figures from all steps during the mantis-ml run (e.g. Exploratory Data Analysis/EDA, supervised-learning, unsupervised-learning) can be found under [output_dir]/Output-Figures.

mantisml-profiler

Preview selected phenotypes and features (optional)

You may preview all selected phenotypes and relevant features based on your input config file parameters by running the mantisml-profiler command.

To run mantisml-profiler, you need to provide a config file (.yaml) and an output directory.

mantisml-profiler [-v] -c [config_file] -o [output_dir]

mantisml-overlap

Run enrichment test between mantis-ml predictions and an external ranked gene list to get refined gene predictions

To run mantisml-overlap, you need to provide a config file (.yaml), an output directory with mantisml results and an external ranked gene list file (mantisml has to be run already given the same ouput directory).

mantisml-overlap -c [config_file] -o [output_dir] -e [external_ranked_file]

mantisml-overlap external ranked file [-e]

The external ranked gene list file may contain a single column with ranked genes or two columns (tab-delimited), with the 2nd column containing p-values. Examples of external ranked lists for both cases are available at example-input.

mantisml-overlap Output

Results are available under [output_dir]/Overlap-Enrichment-Results.

• mantisml-overlap generates figures with the enrichment signal between mantis-ml predictions and the external ranked file, based on a hypergeometric test. These can be found under: Overlap-Enrichment-Results/hypergeom-enrichment-figures.

• mantisml-overlap also extracts consensus gene predictions with support by multiple classifiers. Results can be found at Overlap-Enrichment-Results/Gene-Predictions-After-Overlap.