Is Alcoholism Genetic? Research paper

1)***OPENING QUOTE QUOTE ON GENES WITH ALCOHOLISM \"Alcohol dependence and dependence on other drugs frequently co-occur, and strong evidence suggests that both disorders are, at least in part, influenced by genetic factors. In recent years, researchers have identified numerous genes as affecting risk for dependence on alcohol and drugs. These include genes involved in alcohol metabolism as well as in the transmission of nerve cell signals and modulation of nerve cell activity.\"

2) ALCOHOLISM DEFINITION Alcoholism is a chronic and often progressive disease that includes problems controlling your drinking, being preoccupied with alcohol, continuing to use alcohol even when it causes problems, having to drink more to get the same effect (physical dependence), or having withdrawal symptoms when you rapidly decrease or stop drinking.

3) FACTORS OF ALCOHOLISM Alcoholism and alcohol abuse are due to many interconnected factors, including genetics, how you were raised, your social environment, and your emotional health

4) GENETICS DEFINITION Genetics is the scientific study about the ways characteristics of living things such as eye color or nose shapes or genetic conditions are passed from one generation to the next.

6) GENE EXPRESSION As we have learned more about the role genes play in our health, researchers have discovered that different factors can alter the expression of our genes. This field is called epigenetics. Scientists are learning more and more about how epigenetics can affect our risk for developing alcoholism.

5) GENETICS AND ALCOHOLISM While scientists have known for some time that genetics play a role in alcoholism and other addictions, they also understand the tendency to be dependent on alcohol is more complicated than the simple presence or absence of any one gene

9)THE ROLE GENES PLAY Multiple genes play a role in a person's risk for developing alcoholism. There are genes that increase a person's risk, as well as those that may decrease that risk, directly or indirectly.

**EXAMPLE OF THE EFFECTS OF GENES For instance, some people of Asian descent carry a gene variant that alters their rate of alcohol metabolism, causing them to have symptoms like flushing, nausea, and rapid heartbeat when they drink.

**ADH GENE AND ALCOHOLISM The contribution of genetic factors to the development of alcohol dependence is high [1-4] but nevertheless, knowledge about the specific genes underlying alcohol dependence is currently very limited. The best classical candidate genes for alcohol dependence are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) [17]. Both genes are involved in enzymatic degradation of alcohol.

**ALCOHOLISM GENETICS IN THE BRAIN Receptors in the brain that are highly sensitive to alcohol may function differently in a person with a family history of alcoholism

**PROTEINS IN BRAIN AND ALCOHOLSIM The production of serotonin, another brain neurotransmitter, is also controlled by genes and could be another factor in the link between alcoholism and heredity. Serotonin influences risk-taking behavior, and could influence people to drink more than is safe, which may lead to alcoholism.

**GENES EFFECT TREATMENT Scientists are also exploring how genes may influence the effectiveness of treatments for alcoholism. For instance, the drug naltrexone has been shown to help some, but not all, alcohol-dependent patients to reduce their drinking. Research has shown that alcoholic patients with variations in a specific gene respond positively to treatment with the drug, while those without the specific gene do not.

**DOPAMINE AND ALCOHOLISM The brain's dopamine system is also likely to be involved in the development of alcoholism. Dopamine is a neurotransmitter in the brain that makes people feel pleasure. People with problems in the dopamine production and use systems are more likely to become addicted to drugs of all kinds, including alcohol.

**ALCOHOL GENE Another gene variant that might affect alcoholism is the gene that controls a protein called beta-endorphin. This protein is produced in the brain to numb pain. People with low levels of beta-endorphin sometimes turn to alcohol to numb physical and emotional pain because the body is not doing the job well enough itself. Many alcoholics have the gene for low beta-endorphin production, and when their children inherit this gene, it raises the risk of developing the disease as well.

10) GENE STUDY Philibert et al. conducted a genome-wide study on the effect of recent alcohol use on the epigenome [77]. Here, the authors compared DNA methylation of females which did not consume alcohol in the last 6 months to methylation patterns of females consuming alcohol mildly (use of alcohol in between 1 and 8 weeks in the last 6 month), moderately (use of alcohol in between 9 and 25 weeks in the last 6 month), or heavily (alcohol use in every week in the last 6 month). By doing this, they found the overall degree of methylation to be (nonsignificantly) positively associated with the amount of alcohol consumed. When the moderate and heavy drinkers are pooled together and compared to the non-consuming participants, a probe located in the active BCR-related (ABR) gene, and in the 5` untranslated region of the Bladder cancer-associated protein gene (BLCAP) reached genome-wide significance after correction for multiple testing. However, only 4 of the heavy drinkers investigated met the criteria for a lifetime diagnosis of alcohol dependence, therefore this result needs further replication in a sample of alcohol dependent patients compared to control individuals.

11) ALCOHOLISM GENE The DRD2 gene is the first candidate gene that has shown promise of an association with alcoholism (Gordis et al., 1990).

**OPENING TO GENES AND ALCOHOLISM There is a growing body of evidence highlighting the importance of genetic and epigenetic factors in the development and maintenance of alcohol dependence.

**COGA (Collaborative Studies on the Genetics of Alcoholism) Because alcoholism is a complex genetic disorder, the COGA researchers expected that multiple genes would contribute to the risk. In other words, there will be no single \"gene for alcoholism\" but rather variations in many different genes that together, interacting with the environment, place some people at significantly higher risk for the disease.

12) IDENTICAL TWINS AND ALCOHOLISM Studies with identical twins, who share the exact same genes, demonstrate that if one twin becomes an alcoholic, the other is very likely to have the disease as well. The same is not seen in fraternal twins as they have their own unique sets of genes The evidence favors heredity with figures like 60% (identical) versus 39% (fraternal) in one Scandinavian study.

13) GENE STUDIES A study in Sweden followed alcohol use in twins who were adopted as children and reared apart. The incidence of alcoholism was slightly higher among people who were exposed to alcoholism only through their adoptive families. However, it was dramatically higher among the twins whose biological fathers were alcoholics, regardless of the presence of alcoholism in their adoptive families.

14) DRINKING CONTROL STUDY The study included 45 healthy subjects, some with a family history of alcoholism and others with no family history. None of the study participants had a drinking problem. All of the participants were administered a placebo or ketamine, an anesthetic that induces alcohol-like effects. Their behavioral responses were then observed. People with a family history of alcoholism were less sensitive to ketamine. This study confirms a hypothesis that people with a family history of alcoholism are more vulnerable to alcoholism because they are less likely to get the 'warning signs' of when to stop drinking,\" said Ismene Petrakis, M.D., associate professor of psychiatry. \"In the right environmental and social context, the loss of a potentially important 'brake' on drinking may promote heavy drinking.\"

15) STATISTICS Statistics show that over 40 percent of individuals suffering from alcoholism were genetically predisposed to this disease. However, not all individuals with a genetic predisposition to alcoholism become alcoholics. In those who either never drink or drink occasionally, these genes will lay dormant, but heavy drinkers who are predisposed to alcoholism can become addicted to alcohol rather quickly.

16) STAT ON HERITABILITY The heritability of alcohol dependence is well recognized and heritability estimates range between 40 and 70%

**ALCOHOLIC RELATIONSHIPS One thing behind the connection between alcoholism and heredity may be a predisposition to enjoy alcohol more than other people. People who are closely related to an alcoholic, including brothers, sisters, and children, have a more positive reaction to alcoholic drinks. This may be because they have a gene that makes alcohol use more pleasurable, which could make addiction more likely

**CHILDREN OF ALCOHOLICS Children of alcoholics are about four times more likely than the general population to develop alcohol problems. \"The development of alcoholism among individuals with a family history of alcoholism is about four to eight times more common than it is among individuals with no such family history,\" said William R. Lovallo, Director of the Behavioral Sciences Laboratories at the Veterans Affairs Medical Center, Oklahoma City

COUNTER ARGUMENT With so many genetic factors involved, it can be tempting to think of alcoholism as a purely genetic disease. However, some people with none of the known genetic factors and no family history of alcoholism still become addicted. This is because the social and environmental factors can be strong enough in some cases to cause alcoholism even though the person is at lower risk genetically. Social pressure, in the form of friends and colleagues who drink heavily, is a big factor in the development of alcoholism. A tendency to view alcohol as a form of stress relief or as a way to become less nervous in social situations can also make alcoholism more likely, even if the genetic influences are minimal.

\"Even more interesting are the results from adoption studies. When adopted in infancy and studied into adulthood, sons of alcoholics were 4 times as likely to be alcoholic as were sons of non-alcoholics. And this risk was not affected by the alcoholism status of the adopted parent!

\"Although the genetic bases of alcoholism remain largely unknown, there are reasons to think that more genes will be discovered in the future. Multiple and complementary approaches will be required to piece together the mosaic of causation.\" - Dr. Boris Tabakoff and his team at the University of Colorado-Denver

CONCLUSION ALCOHOLISM IN FAMILIES People who have a family history of alcoholism or who associate closely with heavy drinkers are more likely to develop drinking problems

###GENES AND ALCOHOLSIM/OTHER FACTORS Research shows that genes are responsible for about half of the risk for alcoholism. Therefore, genes alone do not determine whether someone will become an alcoholic. Environmental factors, as well as gene and environment interactions account for the remainder of the risk.*

###Genes explain about 60 percent of the risk for alcoholism, while the environment accounts for the rest,

###GENES WITH ALCOHOLISM FACTS One gene has been discovered that seems to make people get drunk more quickly. This gene is found in 10 to 20 percent of the population. Another gene discovery indicates that a gene we all share may have variations in some people that lead to alcoholism. The gene is related to impulsive behaviors, which are characteristic of people who lose control when drinking. Other genes have been found that help prevent alcoholism.

###HALF FROM GENES While outside factors can lead to alcoholism, nearly half the risk comes from our genes.