Genomic and Environmental Contributions to Chronic Diseases in Urban Populations

Abstract

Uncovering the interaction between genomes and the environment is a principal challenge of modern genomics and preventive medicine. While theoretical models are well defined, little is known of the GxE interactions in humans. We used a system biology approach to comprehensively assess the interactions between 1.6 million environmental exposure data, health, and expression phenotypes, together with whole genome genetic variation, for [~]1000 individuals from a founder-population in Quebec. We reveal a substantial impact of the urbanization gradient on the transcriptome and clinical endophenotypes, overpowering that of genetic ancestry. In detail, air pollution impacts gene expression and pathways affecting cardio-metabolic and respiratory traits when controlling for genetic ancestry. Finally, we capture 34 clinically associated expression quantitative trait loci that interact with the environment (air pollution). Our findings demonstrate how the local environment directly affects chronic disease development, and that genetic variation, including rare variants, can modulate individuals response to environmental challenges.\n\nHighlightsO_LIFine scale environmental effects overpower those of ancestry on gene expression\nC_LIO_LIAir pollution (geographic and temporal) is associated with transcriptional response\nC_LIO_LIGene-by-environment interactions with air pollution include asthma associated loci\nC_LIO_LIInflammatory pathways and cardio-respiratory clinical traits are among those affected\nC_LI