Genetic factors susceptibility genes

It is important to point out that deletion of individual genes is not providing animal models for certain behavioral pathologies that are caused by a manifold of minor changes in a series of so-called susceptibility genes. To make a clinical phenotype overt, a number of exogenous factors, e.g., stressful life events and a susceptible genetic endowment, need to interact in at least most of the cases... 

Studies in twins have suggested that genetic factors may be important in the development of alcoholic liver damage. While there are differences in the various enzymes involved with alcohol metabolism, some of the differences are not consistent or large enough to account for differences in susceptibility. Genetic differences in protective mechanisms and genes involved with inflammation have also been linked to susceptibility to alcohol-induced liver disease. 

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