Genetic factors in determining susceptibility to alcohol dependence and development of alcohol-induced liver disease

There is considerable evidence in favour of genetic factors influencing excessive drinking behaviour and development of alcohol dependence (alcoholism), although readily identified markers of these genes have not been established. In addition, environmental factors undoubtedly play an important role. Although the probability of developing a significant liver disease (alcohol-induced hepatitis with or without cirrhosis) is related to the amount of alcohol ingested, there is a great variation in susceptibility which presumably stems from either genetic or additional environmental influences. The probable linkage of development of severe alcohol-induced liver disease with alleles of the HLA-B locus would suggest the influence of a gene(s) on chromosome 6. Such a gene may determine the rate or type of metabolism of alcohol or, since the immune response genes are present on chromosome 6, may indicate genetically controlled variation in the level of the immune and inflammatory response to alcohol-induced changes in liver membrane antigenicity. Further studies are needed to confirm these associations and to determine the type of factor involved.