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Genetically determined susceptibility to malaria

Report describing the work is in report.pdf file.

To reproduce our results:

  1. Download dataset from here and put it under "data" directory in the repo root.
  2. Create conda environment from environment.yml and activate it by running:
    conda env create -f environment.yml
    conda activate ntds_2019 
    
  3. Execute the jupyter notebooks in the following order:
    1. baseline_phenotype_predictor.ipynb
    2. coexpression_graph_construction.ipynb
    3. coexpression_graph_exploration.ipynb
    4. SNP_expression_imputation.ipynb

Stages of the project

  1. Exploratory Data Analysis
    • Obtain PhenoID for diseases of interest (Malaria and Influenza)
    • Get phenotype value associated to the PhenoID of interest for each mouse
    • Check distribution of phenotype values obtained previously
    • Select single phenotype for simplicity: malaria susceptibility
    • Normalize the data: subtract mean and divide by standard deviation
    • Building a dataframe of all (SNP expression, tissue) pairs for all mice for constructing the coexpression graph
  2. Setting a baseline
    • Building a regression model, ridge regression and random forests, to predict phenotype values given genes expression. We take all expressions and filling missing values with mean
  3. Building co-expression graph
    • (Genes, Tissue) as node and we use the expression values of each mouse to compute the distance metric.
  4. Imputation of SNP expression on co-expression graph using Tikhonov filter
    • Smoothing for filling missing values for SNP expression
  5. Prediction of phenotype values using additional expression data from 4.
    • Using the best method, comparing with baseline.