Faculty Opinions recommendation of Gene-environment interaction study for BMI reveals interactions between genetic factors and physical activity, alcohol consumption and socioeconomic status.
This is one of the first studies to come out of the UK Biobank exploring genotype-by-environment interactions. Since there is little power to see effects at the individual genotype level, the authors instead adopt a polygenic risk score-by-environment (GRSxE) approach, specifically related to body mass index (BMI). They conclude that polygenic effects are influenced by 15 of the 131 lifestyle factors investigated, the strongest being exercise, alcohol consumption and socioeconomic status. This is certainly relevant to understanding that disease risk is shaped by both the environment and the genome, and makes intuitive sense, also backed by Urko Marigorta’s (2014) simulation studies of GRSxE {1}. Some aspects of the presentation look a bit rushed (Table 1 percentages for example don’t add up), and it is notable that the replication must have been generated within a couple of weeks of the release of the full UK Biobank genotypes. The findings should also be considered in light of Matt Robinson and coworker’s recent appraisal of the relatively small influence of environment on heritability of height and BMI {2}.