Beyond the genes encoding these metabolic enzymes, there are probably at least hundreds to thousands of additional genes, interacting with the environment, that affect the risk for AUDs and excessive alcohol consumption. With the exception of the protection offered by homozygosity for ALDH2*2, no one gene or combination of genes is determinative. Understanding which other genes affect risk, and the mechanisms by which they do, should enable progress in prevention and treatment. Much larger, well-characterized samples are needed to identify these variants of small effect, and thereby to better understand AUDs and the other effects of alcohol. Even variants that individually make only a very small contribution to risk can reveal key pathways and mechanisms of risk, which can then be targeted for treatment and prevention.
