What is the role of genetics in addiction?

Partial: There is a familial component, but addiction is a very complex process. Many children of addicts emerge without addictions. Nevertheless, because risk is increased, people whose family members have struggled with addiction should regard all substances, including alcohol and tobacco, with caution, practice abstinence or moderation, and seek prompt help for any concerns about over-use or dependence.

Genetis of addiction: Wang et al 2012 answered this question nicely. The most well-established genetic factors associated with alcohol dependence are in the genes encoding alcohol dehydrogenase (adh), which oxidizes alcohol to acetaldehyde, and aldehyde dehydrogenase (aldh2), which oxidizes newly developed dna sequencing technologies could potentially advance the findings of other genes soon to be published.