It is quite unfortunate that Linda aunt is hospitalized with liver disease. Hope she is responding well to the treatments. Anyway, I appreciate her goodwill to co operate with the scientific study about genetics of alcoholism. It is a good move she made at this time. More focused treatments can be given with this attempt. Further, Genetic studies will help you to understand more about the heritability of alcohol dependence and which will positively help you to explore the correlation of alcoholism to other disorders like major depression.
You might have heard that Alcoholism is a chronic disease. Statistics says that more than seventy six million people around the world are affected by this severe syndrome (UCSF, p.1). The reaction of people towards alcohol will be different. Some people are social drinkers but others develop severe and disruptive drinking habits. As far as I realize, your mom is a victim of this troublesome drinking habit. Like many other human disorders, this inconsistency of alcohol consumption is influenced by both heredity (biological factors) and environment. As you know, Genetic predispositions are the hereditary aspect of alcohol dependence.
As per the statistics, about 50% of alcohol dependence is linked with genetic factors and the other half includes the environmental factors. Greater Dallas council which deals with alcohol & drug abuse suggests that alcoholism is greatly related to heredity as there are research evidences confirming this. According to the twin studies conducted by Pickens and coworkers identical twins showed higher similarity of alcohol reliance compared to fraternal twins (Pickens, 19-28). Another reality is that Males are four times more vulnerable to alcoholism than females.
Numerous researches are going on around the world on the issues of alcoholism. According to Collaborative Study of the Genetics of Alcoholism (COGA), it is possible to find an important relation between vulnerability for alcoholism and the chromosomes 1 and 7. Mary-Anne Enoch, a research physician of NIAAA, identified a new genotype named COMT Met 158Met. Among European men, this genotype is coupled with late onset of alcoholism and increased alcohol consumption. The same genotype is found to be associated with increased anxiety and reserve. Another study found that a gene on chromosome- 10, the KCNMA1 gene is linked to the level of response to alcohol. (Alcohol: Clinical Experiment Research, 2005). So far, ADH1 group and ADH4 group are the only gene variants that are known to influence our drinking habits, which code the proteins to metabolize ethyl alcohol to acetaldehyde. (Nurnberger; Nurnberger) However, investigations like Human Genome Project is now near to decode the whole genetic composition of the human genetic code.
As your doctor told, people having a genetic record of either alcoholism or depression will be at high risk to develop either of these illnesses. According to COGA, there is a greater possibility for depressive syndrome among alcoholic subjects. The combination of the phenotypes (Traits) Alcoholism and depression can hit more upon the members of a family. As the evidences of COGA suggests, there is an important relation between gene and chromosome 1, which is linked to alcoholism in some people and the same gene predisposes depression among others. A study by Washington University established some similarities on Chromosome 7 among people from alcoholic families and in depressed people. Yet another gene, engaged in many important brain functions is strongly associated both with alcoholism and depression is CHRM2 in chromosome 7. Among Individuals having both alcoholism and depression, the association is found strongest (Wang JC, et al., pp. 1903-1911). About sixty percent of major depression is transmissible to the other generation. The relatives of alcoholics are more vulnerable to alcoholism along with secondary depression if depression occurred in the alcoholic due to alcohol dependence. Likewise, relatives of non-depressed alcoholics are at high risk to develop alcohol dependence. (Nurnberger 2001). Alcohol abuse precedes depression among men. On the contrary, depression paves the way to alcohol abuse among women. (Study Links Depression and Alcohol Problems, 1997).
Alcohol abuse influences your life expectancy and it will definitely influence your life insurance premiums. Hence, the insurance companies will be keen to know about your habits of drinking. However, social drinking will not affect your insurance rate. If you are a problem drinker, some factors like the history of alcohol dependence, treatments taken, post treatment record, the network of support, medical records of the illness, driving records and your lab results will determine your appropriate insurance premium rates (How Alcohol use Affects your Life Insurance Premiums).
Just because of someone has a heritability of a disease like alcoholism; it does not mean that they will certainly develop that disease; just be conscious that such people are at high risk than the others. However, to influence diseases like depression or alcoholism, both heredity and environment have to work together than genetic factors alone. Hence, you do keep an optimistic outlook than getting nervous about your genes.
Works Cited
Alcohol. Greater Dallas Council on Alcohol & Drug Abuse. 2006. Web.
How Alcohol use Affects your Life Insurance Premiums. 2008. Web.
Kalat, J. W. Biological Psychology, 5th edn., USA: Books/Cole Publishing Company, 1995.
Nurnberger, John I. Seeking the Connections: Alcoholism and Our Genes. Scientific American. 2008. Web.
Pickens, R.W., Svikis, D. S., McGue, M., Lykken, D. T., Heston, L. L., & Clayton, P. J. Heterogeneity in the Inheritance of Alcoholism. Archives of General Psychiatry, 1991, Vol. 48.
Study Links Depression and Alcohol Problems. Washington Post Health, American Journal of Epidemiology, 1997. UCSF Family Alcoholism Study. 2002. Web.
Wang, J. C, et al, Evidence of Common and Specific Genetic EEffects: Association of the Muscarinic Acetylcholine Receptor M2 (CHRM2) Gene with Alcohol Dependence and Major Depressive Syndrome. Human Molecular Genetics, 2004, vol. 13:17.