Using population biobanks to understand complex traits, rare diseases, and their shared genetic architecture

The study of the role of genetic variability in common traits has led to a growing number of studies aimed at representing whole populations. These studies gather multiple layers of information on healthy and non-healthy individuals at large scales, constituting what is known as population biobanks.
In this thesis I took advantage of the potential of these population biobanks to measure the influence of genetic variation in common and rare traits. I explored the mechanisms behind these by exploring their interaction with conditions, physiological measurements, and habits in general and healthy population. First, I used the Lifelines cohort, with genetic information of Dutch population. Here, my colleagues and I explored traits with different levels of genetic influence we uncovered associations between both Blood type and dairy consumption with human gut microbiome function and composition, and we identified a protective factor for a rare type of cardiomyopathy with potential use for diagnosis.
Additionally, within a global collaboration across world-wide biobanks totaling > 2 million individuals, we demonstrated the robustness of the connections between genetic variation and 14 different diseases across the populations. We also provided methodological guidance for the combination of the effects of genetic variation to calculate the risk of disease in studies including biobanks with populations of different ethnic backgrounds.
Overall, my PhD research contributed on identifying and validating which factors are relevant for potential clinical applications, and provided guidelines to be used in future genetic studies on common traits and diseases at a global scale.