We are interested in how genotypic variability impacts molecular phenotypes and how, together with the environment, this affects complex human traits and disease susceptibility. Our focal molecular phenotype involves the concentration of small molecules underlying metabolism. These concentrations can be measured on large-scale, in body fluids, like blood and urine. In our recent article “Genome-wide association study of metabolic traits reveals novel gene-metabolite-disease links” that appeared in PLoS Genetics on 20 February 2013, we studied such data derived from the CoLaus. Below is more information on this publication and details on the our method can be found here. Our article features as News of the University of Lausanne (here), the University Hospital -CHUV (here) and the Swiss Institute of Bioinformatics (here).

The concentrations of small molecules, known as metabolites, are subject to tight regulation in all organisms. Collectively, the metabolite concentrations make up the metabolome, which differs amongst individuals as a function of their environment and genetic makeup. In our study, we have further developed an untargeted approach to identify genetic factors affecting human metabolism. In this approach, we first identify all genetic variants that correlate with any of the measured metabolome features in a large set of individuals. For these variants, we then compute a profile of significance for association with all features, generating a signature that facilitates the expert or computational identification of the metabolite whose concentration is most likely affected by the genetic variant at hand. Our study replicated many of the previously reported genetically driven variations in human metabolism and revealed two new striking examples of genetic variations with a sizeable effect on the urine metabolome. Interestingly, in these two gene-metabolite pairs both the gene and the affected metabolite are related to human diseases – Crohn’s disease in the first case, and kidney disease in the second. This highlights the connection between genetic predispositions, affected metabolites, and human health.