Genome-wide association studies (GWAS) have been critical in identifying thousands of genetic variants associated with complex traits and diseases. For certain complex traits however, it may be the case that there is difficulty in phenotypic measurement and this can lead to issues of statistical power. This is particularly problematic for behavioural phenotypes that may be predominantly determined by the environment, as is the case for educational attainment and well-being (Okbay et al., 2016; Okbay et al., 2016; Rietveld et al., 2013). Genetic analyses of such phenotypes can be hindered by the fact that individual SNPs have limited explanatory power and any associations found may not be causal or may be mediated by many other intermediate phenotypes (Krapohl et al., 2014). However, such studies have enabled the description of common genetic contributions to complex behaviours. Taken together, these GWAS results form a pool of genetic variants which may then be used in Mendelian randomization (MR) analyses; both looking at the effect of these features on outcomes but also the effect of outcomes on them.

This project will use newly collected data in the Avon Longitudinal Study of Parents and Children cohort to analyse voting behaviour. Firstly, we aim to conduct a GWAS on voting behaviour to discover any genetic variants associated with this complex trait. Additionally, we plan on considering the potential of using MR analysis to look at this behavioural phenotype. Specifically, we aim look at the effect of well instrumented risk factors on voting behaviour itself, i.e. ‘backwards MR’.

References
Krapohl, E. et al. The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence. Proc. Natl Acad. Sci. USA 111, 15273–15278 (2014).

Okbay, A. et al. Genetic variants associated with subjective well-being, depressive symptoms, and neuroticism identified through genome-wide analyses (vol 48, pg 624, 2016). Nature Genetics 48, 1591-1591 (2016).

Okbay, A. et al. Genome-wide association study identifies 74 loci associated with educational attainment. Nature 533, 539-+ (2016).

Rietveld, C.A. et al. GWAS of 126,559 Individuals Identifies Genetic Variants Associated with Educational Attainment. Science 340, 1467-1471 (2013).