Gene-environment Interaction: The Causes of High Obesity Incidence.

Urbanization has provided experimental settings for testing the interactive relationship between genetic background and changes in lifestyle and dietary patterns. The concept of gene-environment interaction was described by epidemic of obesity along with urbanization. Genome-wide association has identified several genes such as melanocortin-4 receptor that associates with environmental influences of obesity. Gene environment (GxE) interaction refers to modification by an environmental factor of the effect of a genetic variant on a phenotypic trait. GxE interactions can serve to modulate the adverse effects of a risk allele, or can exacerbate the genotype-phenotype relationship and increase risk.