Investigating the Role of Gene-Gene Interactions in TB Susceptibility

PLoS One. 2015 Apr 28;10(4):e0123970. doi: 10.1371/journal.pone.0123970. eCollection 2014.

Abstract

Tuberculosis (TB) is the second leading cause of mortality from infectious disease worldwide. One of the factors involved in developing disease is the genetics of the host, yet the field of TB susceptibility genetics has not yielded the answers that were expected. A commonly posited explanation for the missing heritability of complex disease is gene-gene interactions, also referred to as epistasis. In this study we investigate the role of gene-gene interactions in genetic susceptibility to TB using a cohort recruited from a high TB incidence community from Cape Town, South Africa. Our discovery data set incorporates genotypes from a large a number of candidate gene studies as well as genome-wide data. After limiting our search space to pairs of putative TB susceptibility genes, as well as pairs of genes that have been curated in online databases as potential interactors, we use statistical modelling to identify pairs of interacting SNPs. We attempt to validate the top models identified in our discovery data set using an independent genome-wide TB case-control data set from The Gambia. A number of models were successfully validated, indicating that interplay between the NRG1 - NRG3, GRIK1 - GRIK3 and IL23R - ATG4C gene pairs may modify susceptibility to TB. Gene pairs involved in the NF-κB pathway were also identified in the discovery data set (SFTPD - NOD2, ISG15 - TLR8 and NLRC5 - IL12RB1), but could not be tested in the Gambian study group due to lack of overlapping data.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Epistasis, Genetic*
  • Gambia / epidemiology
  • Gene Regulatory Networks
  • Genetic Predisposition to Disease*
  • Humans
  • Models, Genetic
  • Models, Statistical
  • Polymorphism, Single Nucleotide*
  • Signal Transduction
  • South Africa / epidemiology
  • Tuberculosis / epidemiology
  • Tuberculosis / genetics*

Grants and funding

South African National Research Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.