Genetic factors in alcohol use-a genetic epidemiological perspective

The purpose of this paper is to put a genetic epidemiological perspective on the role of genetic factors involved in the susceptibility and expression of alcohol use. The consequences of familial aggregation in a trait is explained, and the evidence for familial aggregation in alcoholism is viewed critically. Methods for making inference about unmeasured genetic factors from family-based studies of twins, adoptees, etc. are examined. The meaning and limitations of "heritability" are explained. A summary of the literature regarding the possible role of genetic factors on several aspects of alcohol use, including alcohol metabolism, is presented. Some of the evidence for measured genetic factors related to alcoholism and alcohol use is examined. The basic requirements for justifying genetic screening for an adult onset condition, such as alcoholism, are outlined. It is concluded that, although behavioural geneticists have tended to overstate the case for a genetic aetiology, it may only be a matter of time before one or more genetic loci, which in some part determine susceptibility to problem drinking and alcohol abuse, are identified. Genetic screening programmes, however, are unlikely to be justified, especially given the lack of proven prevention strategies.