Alcoholism and Genetics: Is There an Inherited Family Alcohol Gene?

Alcoholism is a term that refers to alcohol addiction or, according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), alcohol use disorder (AUD). The condition is marked with excessive alcohol consumption that can become severe, resulting in problem drinking, alcohol dependence or becoming an “alcoholic.”Heavy drinkers who are affected usually display compulsive behaviors as well as physical dependence with high alcohol consumption. AUD affects an estimated 16 million Americans. This number is made up of 15.1 million adults over the age of 18 and over 600,000 adolescents between the ages of 12 and 17. In other words, a lot of people are affected by this condition—and not just the effects of alcohol through consumption—that can be categorized as a form of substance abuse. As such, much research has been geared toward understanding what exactly causes it. Once that is known, approaches toward better treatment can be taken much more effectively.

So, what exactly causes alcohol use disorder? Since it is a form of addiction, it is safe to assume that the triggers of alcohol problems are similar for both categories, namely gender, environment, mental health status, family history as well as genetics. If you are surprised to hear that even AUD has genetic underpinnings, just remember that scientific and technological progress has enabled researchers to understand that a plethora of diseases and conditions is due to the information that is stored in genes. Furthermore, not only does AUD have a genetic background, researchers estimate that genetic risk constitutes about half the problem of alcohol addiction with the other half being family history. You may think that this makes sense since genes and genetic traits are shared among families, but that is not always the case since family history also takes into consideration the environment in which one was raised that may have had an impact without any genetic background.

The possible genes that are involved in AUD have been revealed a few years ago. In 2012, a group of scientists was able to narrow things down to 11 genes. The findings were initially based on a study that was conducted in mice, and the discovered associated genes were then also found in groups of humans. Interestingly, these genes were also associated with neuropsychiatric disorders such as Parkinson’s Disease, cocaine addiction, bipolar disorder, schizophrenia,and anxiety.

Some genes can help individuals control their alcohol intake and maintain it at a normal level. At the same time, other genes increase the person’s risk of alcohol abuse. Three of the eleven genes that were discovered are listed below:

Schizoaffective Disorder

GABRB1 – This stands for Gamma-Aminobutyric Acid Type A Receptor Beta 1 Subunit and the gene codes for a specific protein. It is associated with diseases such as Epileptic Encephalopathy, Early Infantile, 45 and Schizoaffective Disorder. Research has shown that mutations in this gene are associated with an increased risk of AUD because it causes changes to GABA, which has a lot to do with how a person feels. Alcohol, specifically, has been shown to induce changes that result in relaxation as well as anxiety and/or stress relief. Someone with a mutated form of GABRB1 may produce less GABA and may not feel so well when sober (maybe due to withdrawal symptoms or similar), therefore looking to alcohol to feel better, not realizing that it is alcohol abuse or the risk factors involved.

ADH1B – The Alcohol Dehydrogenase 1B Beta Polypeptide is also a protein-coding gene. It is much more prevalent among the Asian population than among Europeans. Approximately 70 percent of East Asians have this gene, while its prevalence among European populations is only about 5%. ADH1B variants are associated with symptoms such as a flush reaction during which people feel hot and sweaty, their faces become red, and they feel discomfort such as sickness. The gene is responsible for regulating the liver. More specifically, it is associated with the liver’s ability to break down alcohol to acetaldehyde, which is further degraded to acetate. The flush reaction is a result of too much acetaldehyde not being metabolized into acetate. However, this gene is viewed a little differently, in the sense that it is considered to be a deterrent from AUD due to its effects. In other words, among populations where it is prevalent more, AUD seems to be less of a problem, and vice versa. Among Europeans, the risk of developing AUD is much higher with an ADH1B prevalence being so low.

Beta-Klotho – Individuals who carry this gene actually consume less alcohol than those who are not carriers. Those who have this gene are much more successful at stopping after one or two drinks than those who are not carriers and appear to be much less able to control their urges. Two hormones are said to trigger this gene, and this process can also determine if the person has a sweet tooth and prefer sweet and sugary tastes. Ultimately, this gene is associated with AUD as those who do not have it appear to be much less able to control their urges and are much more likely to develop the condition.

While animal studies, by virtue of being based on research that involves rodents that are bred with a specific condition, have been effective indicators of AUD, longitudinal human studies have also been conducted. These unanimously point to the importance of the environment when it comes to risks of developing AUD. Individuals who grow up in stressful environments, who have been exposed to trauma and who grew among families that have a history of drug abuse or mental illness are said to be much more likely to develop AUD.

Ultimately, regardless of background, family history and/or genetic predispositions, if drinking becomes out of control on a regular basis, individuals are advised to discuss their problems with a physician who can point them to the best therapies possible.

Laura Day
 

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