The Alcoholic Gene
Why can someone have one alcoholic beverage and stop, while others drink until they blackout? We all know that one friend who takes it a too far with drinking or the guy at the bar who drinks himself into oblivion. More shockingly, there are people that repeat this vicious cycle weekly, or even daily. How can scientists explain this behavior? Could it be their environment or perhaps genetics passed down in the family? According to investigators from the Washington University School of Medicine, an “alcoholic gene” is likely.
They found a gene called GABRG3 within chromosome 15 that was linked to alcoholism in the experiment. This is not to be confused with family attitudes about alcohol consumption. There are many families that drink more than others and although this plays a role in alcohol consumption, the gene GABRG3 separates people who enjoy alcohol and those who abuse it (Dick et. al, 2004).
The study was conducted on 262 families (2,282 individuals), where they isolated and observed three genes (GABRA5, GABRB3, and GABRG3) found on chromosome 15. People that were dependent on alcohol had a GABRG3 gene in the majority of cases. This experiment indicates that GABRG3 may cause a hyper excitable nervous system, leading to alcoholism to self-medicate. This data gave way to further evidence of how GABA relates to alcoholism, since the GABRG3 gene plays a role in how GABA function. However, there are a variety of genes and environmental factors that can contribute to alcoholism and scientists still do not understand why certain genes and/or gene interactions can result in a higher dependency for alcohol (Dick et. al, 2004).
To conclude, although there is speculation as to what gene affects alcoholism more than others, it is evident that certain genes affect human consumption. More importantly, there is a crucial link between GABA transmitters and alcoholism. Further studies should be conducted that observe more genes that regulate anxiety and their relation to alcohol dependence. Another study that appeared on the Journal of Neuroscience observed a different gene that is potentially responsible for alcoholism. CREB, a gene that regulates anxiety, brain function for learning, and alcohol tolerance, was studied in mice. Mice were offered alcohol and the ones that lacked the CREB gene drank 50% more alcohol than CREB sufficient mice. The Deficient CREB mice also showed more signs of anxiety than the control group. The consumption of alcohol decreased their anxiety. The research appears that the lack of the CREB protein was the basis for alcohol dependence in the mice (WebMD, 2004).
Dick, D. M., Edenberg, H. J., Xuei, X., Goate, A., Kuperman, S., Schuckit, M., … Foroud, T. (2004). Association of GABRG3 With Alcohol Dependence. Alcoholism: Clinical & Experimental Research, 28(1), 4-9. doi:10.1097/01.alc.0000108645.54345.98
WebMD. (2004). Researchers Identify Alcoholism Gene. Retrieved from http://www.webmd.com/mental-health/addiction/news/20040526/researchers-identify-alcoholism-gene