Beer and a smoke: genetic link to alcohol tolerance

A gene cluster on chromosome 15 that has been linked to nicotine and alcohol dependence has shown an association with a low level of response to alcohol.

Previous studies have shown that a low level of response – meaning people must drink more to reach the desired level of intoxication – is a risk factor for alcohol use disorders.

Genome wide association studies previously have found a cluster of genes on chromosome 15 have a strong link to nicotine dependence and/or lung cancer in smokers. The genes code for nicotinic acetylcholine receptors and belong to a multigene family.

These loci have also been implicated in susceptibility to alcohol dependence. Both nicotine and alcohol increase the activity of the receptors in the central nervous system.

Now, Raymond White and colleagues from the University of California, San Diego have found that two markers in the CHRNA5-CHRNA3-CHNB4 cluster are also associated with alcohol level of response (LR).

Level of response is considered an intermediate phenotype for alcohol use disorders, the researchers write in a study published today in the US journal Proceedings of the National Academy of Sciences.

The researchers write that a strong link between genetic loci for both alcohol dependence and level of response indicates this is a suitable target for further genetic studies.

“Chromosome 15q25.1 genetic markers associated with level of response to alcohol in humans” by Geoff Joslyn et al is published in PNAS [doi:10.1073/pnas.0810970105].