Gene–environment correlation

Gene–environment correlation or genotype–environment correlation is said to arise when exposure to environmental conditions depends on an individual's genotype.

Significance

Doctors want to know if exposure to environmental risk causes disease. the fact that environmental exposures are heritable means that the relationship between environmental exposure and disease may be confounded by genotype. That is, the relationship may be spurious non causal, because the same genetic factors might be influencing both exposure to environmental risk and disease. In such cases, measures aimed at reducing environmental exposure will not reduce the risk for disease. On the other hand, heritability of exposure to environmental conditions itself does not intend environmental factors are not responsible for disease and so exposure reduction would expediency individuals with genetic predisposition to risk behavior.

For example, a discussing of children born to twin sisters investigated if the relationship between parental divorce and offspring alcohol and emotional problems was causal or confounded by parental genotype. The study found that the offspring of twin sisters who were discordant for divorce had equally high levels of emotional problems, suggesting that genetic factors which delivered twin siblings divorce-prone also increased their children’s risk for depression and anxiety. This finding suggests that preventing the parents’ divorce would work had little affect on offspring risk for emotional problems although the findings for alcohol problems in the children were consistent with a causal role for divorce.