«Heritable Genetic Disease» - Free Essay Paper

Introduction

The humans learned how to fermentate milk and grapes in the ancient times. Techniques to concentrate alcohol appeared in the 1000’s AD. Availability of concentrated alcohol spread over Europe in the 13^th – 14^th centuries and paved the way to alcohol abuse (Nayak et al., 2008). Alcoholism is recognized as a complex disease of multiple risk factors - genetic, psychological, and social. Scientists state that if all risk factors are combined, the probability to become an alcoholic during the lifetime is 12% (Kansas State University, 2008). However, alcoholism affects 4-5% of the population. Thus, over the last 40 years, there has been a continuous debate as to what contributes more to the development of alcoholism, heredity or environment. In this paper, the genetic and environmental factors contributing to alcoholism as well as their outcomes are discussed.

Manifestations and Prognosis

Manifestations

Alcoholism is defined as continuing alcohol consumption despite the fact that its usage results in persistent negative consequences. These consequences may be legal problems, difficulties in relationship, financial troubles, health issues, and conflicts at school/work. When an individual tries to stop consuming alcohol, he/she may develop nausea or vomiting, diaphoresis, anxiety, headaches, tremor, seizures, or hallucinations (Thompson, 2015). Chronic alcoholics usually have enlarched liver with various stages of fibrosis or cirrhosis, enlarged spleen, testicular atrophy, gynecomastia, and Dupuytren contractures. Ataxia and confusion in these clients indicate Wernicke encephalopathy, a state of biochemical lesions in the neural system. Amnesia, combined with Wernicke encephalopathy, compose Korsakoff syndrome, when the encephalopathy is excacerbated by toxic influence of alcohol on the brain. Late stage liver disease in patients with alcoholism may induce hepatic encephalopathy, a condition of confusion with uncontrolled hand movements.

Prognosis

This devastating condition eventually leads to mental and physical health problems, which makes the prognosis poor. Alcohol injures all body tissues, but primarily causes most damage to the brain and the liver. Heavy alcohol consumption cuts 10 to 12 years of one’s life (Nayak et al., 2008). Alcohol abuse is the third leading cause of preventable deaths (after obesity and smoking) in the developed world (Thompson, 2015). In the United States, 85,000 of deaths each year attribute to alcoholism (Thompson, 2015). The majority of people die from accidents under the influence of alcohol. Nearly a third die from liver complications. Alcohol is also attributed to cardiomyopathy, pancreatitis, mouth cancer. Around 30% of alcoholics in recovery programs stop drinking, even with alcoholic cirrhosis. However, those patients who have been sober for 2 years, still have a 40% probability to relapse (Nayak et al., 2008; Thompson, 2015).

Risk Outcome

Evidence of Inheritance

Numerous studies support the genetic hypothesis of alcoholism (Kansas State University, 2008; Nayak et al., 2008; Thompson, 2015). The most important of them are as follows.

Family history.

If the parents are alcoholics, 18% of boys will develop alcoholism; the rate for children from non-alcoholic parents is four times lower (Kansas State University, 2008).

Twin studies.

Identical twins with the same genetic material if they are brought up in different social areas show strong similarities (although not identical) to the development of alcoholism (Nayak et al., 2008).

Adoption studies.

Babies from alcoholic parents adopted to non-alcoholic families show significantly higher risks to the development of alcoholism (Kansas State University, 2008; Nayak et al., 2008).

Evidence of Environmental Issues.

It is estimated that an individual is 50% more like to drink heavily if his/her family or friends are alcoholics (Kansas State University, 2008).

Researchers suggest that nearly a half of the probability to develop alcoholism can be attributed to genetics, while the remaining factors are psychological or environmental (Kansas State University, 2008). The following gene patterns have been linked to alcohol dependency. Firstly, metabolism of alcohol dictates the reaction of the organism to its consumption. Alcohol dehydrogenase primarily processes the ethanol consumed by the individual. Certain alcohol dehydrogenase patterns are protective in the Asians and weak in the American Indian tribe descendants. Aldehyde dehydrogenase further degrades alcohol, and its deficiency causes elevated levels of acetaldehyde resulting in increased hangover symptoms. Cytochrome P450 is a liver enzyme that detoxicates the alcohol and its derivatives, its mutations increase the risk of alcoholism.

Secondly, brain chemicals may behave differently in different people. One of the principal neurotransmitters in the brain is γ-aminobutyric acid (GABA). Activation of GABA receptors of the brain cells causes sedation, satisfaction, coordination and dependence. Alcohol directly stimulates the GABA receptors. Some studies suggest innate abnormalities of the GABA system predispose the individual to prefer alcohol (Kansas State University, 2008). Dopamine system is another neurotransmitting network in the brain that is responsible for the pleasure. Alcohol reinforces the action of dopamine in the brain. Low concentrations of dopamine receptors in the neurons or their altered activity predispose the individual to alcoholism. Serotonin is a system responsible for good mood, memory, learning and cooperation with the environment. The alcoholics produce less serotonin, contributing to this disorder.

Thirdly, individuals experience variable sensitivity to odors, including alcohol. Certain GABA system alterations make the individual more sensitive to alcohol aroma, triggering stronger response to its smell (Kansas State University, 2008; Levey et al., 2014; Nayak et al., 2008).

Therefore, researchers have proven recently that at least 11 genes can predict the person to become an alcoholic (Levey et al., 2014). In combination with the predisposing nurture, the risks are even greater. The contributors conclude that genetic predisposition precipitates with physiological drive and mind domains producing alcoholism. However, individuals with genetic predisposition to alcoholism may in fact have a robust psychology and strong behavioral drives. If exposure to alcohol is avoided in these persons, they can be harnessed to productive results.

Conclusion

Alcoholism is a multi-factor disease with poor prognosis and high risk of relapse. Its psychological consequences are grave and physical impacts are lethal. Modern genetic studies explain numerous observations of inheritance of alcoholism. The risks of its manifestation are highest when genetic factors are combined with environmental issues.