Carrier Test
Carrier Test
Genetic testing allows the genetic diagnosis of vulnerabilities to inherited diseases, and can also be used to determine a child’s paternity (genetic father) or a person’s ancestry. Normally, every person carries two copies of every gene (with the exception of genes related to sex-linked traits, which are only inherited from the mother by males), one inherited from their mother, one inherited from their father. The human genome is believed to contain around 20,000-25,000 genes. In addition to studying chromosomes to the level of individual genes, genetic testing/screening in a broader sense includes biochemical tests for the possible presence of genetic diseases, or mutant forms of genes associated with increased risk of developing genetic disorders. Genetic testing/screening identifies changes in chromosomes, genes, or proteins. Most of the time, testing/screening is used to find changes that are associated with inherited disorders. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder. Since genetic testing may open up ethical or psychological problems, genetic testing is often accompanied by genetic counselling, which is the process by which patients or relatives, at risk of an inherited disorder, are advised of the consequences and nature of the disorder, the probability of developing or transmitting it, and the options to them in management and family planning. DNA analysis also has applications in forensic science, enables us to study current health risks, and also to discover the health status of preceding generations from human remains, and to pursue the genetic origins of disease leading to prevention or cure.
Limitations and Ethical issues in Genetic Screening/Testing Biotechnology
One possible limitation of all medical testing is the possibility for laboratory errors. These might be due to sample misidentification, contamination of the chemicals used for testing, or other factors. Many in the medical establishment feel that uncertainties surrounding test interpretation, the current lack of available medical options for these diseases, the tests' potential for provoking anxiety, and risks for discrimination and social stigmatization could outweigh the benefits of testing.
Since these techniques change the flow of information at the level of molecules, the level of individuals, and at the level of societies it is wise to consider to what extent we want to apply these technologies and to reflect on what changes we are seeking. A pertinent question to ask might be whether a technology should be used just because it is available. We need to exercise judgment in our pursuit of these technologies. We also need to understand the options the new genetic technologies will offer so that we can make informed decisions at the individual, local, state, national, and international levels.
One of the problems posed by recent developments in molecular genetics is the actual definition of what constitutes a "disease." There is precedent for defining deviations from the statistical norm, such as high blood pressure or obesity, as "disease." However it is appropriate to ask if a late onset condition is a disease. When the full human genome -- the collective name for all human genes -- is mapped, we risk greatly expanding the numbers of people who do not fit our definitions of normal, able, and healthy.
The significance of the debate about what constitutes a disease is underscored by the two broad questions which underlay the current debate: Who decides whether or not testing is done; and what happens to that information? Clearly genetic screening is going to be done. The question is how are we going to use it and what social limit will we put on it? There is an apparent discrepancy between the reality of genetic variability and the democratic ideal that all citizens are "created equal." Possible outcomes of genetic screening experts see are:
-
Genetic discrimination: People with genetic flaws, not all of which show up as dysfunctions, may be denied life insurance, health insurance, and access to schooling or to jobs.
-
Differential treatment: Employers could hire only those people whose genes indicate that they are resistant to the health hazards of the work place, which is a cheaper alternative to making the work place safe for all.
-
Eugenics: Social or political pressure may be applied to people to make childbearing decisions on the basis of genetic information. Mating between those with valued genes may be encouraged while mating between two people with dangerous recessive traits may be prohibited. Women carrying foetuses with genetic abnormalities may be encouraged to abort.
-
Genetic determinism: Genetic determinism is the belief that behavioural and personality characteristics, such as intelligence or criminal behaviour, are mostly a function of genes. Genetic determinism implies a fatalistic attitude toward health and disease. It can be used to justify bigotry and to perpetuate racial or ethnic inequalities.
Risks and more limitations:
Interpreting results:
The results of genetic tests are not always straightforward, which often makes them challenging to interpret and explain. They may not always be correct. When interpreting test results, healthcare professionals consider a person’s medical history, family history, and the type of genetic test that was done.
In some cases, a negative result might not give any useful information. This type of result is called uninformative, indeterminate, inconclusive, or ambiguous. Uninformative test results sometimes occur because everyone has common, natural variations in their DNA called , which do not affect health. If a genetic test finds a change in DNA that has not been associated with a disorder in other people, it can be difficult to tell whether it is a natural polymorphism or a disease-causing mutation. An uninformative result cannot confirm or rule out a specific diagnosis, and it cannot indicate whether a person has an increased risk of developing a disorder. In some cases, testing other affected and unaffected family members can help clarify this type of result.
Many of the risks associated with genetic testing involve the emotional, social, or financial consequences of the test results. People may feel angry, depressed, anxious, or guilty about their results. In some cases, genetic testing creates tension within a family because the results can reveal information about other family members in addition to the person who is tested. The possibility of genetic discrimination in employment or insurance is also a concern. Some individuals avoid genetic testing out of fear it will affect their ability to purchase insurance or find a job. Genetic testing can provide only limited information about an inherited condition. The test often can't determine if a person will show symptoms of a disorder, how severe the symptoms will be, or whether the disorder will progress over time. Another major limitation is the lack of treatment strategies for many genetic disorders once they are diagnosed.
Government Regulation:
Genetic testing oversight involves a number of organizations, both within and outside of the public sphere. In general, the government plays a leading role in developing regulations to define safety mechanisms for genetic tests, and outlines statutory requirements for the development and usage of these tests. Often, this can involve several government bodies: in the United States, for example, the Federal Food and Drug Administration regulates the development of new tests; the Centers for Medicare and Medicaid Services determine genetic laboratory accreditation; the Centers for Disease Control and Prevention conduct research on current oversight; and the Secretary of Health and Human Services plays a descriptive role in how regulation develops. Beyond that, other actors also play a part, including the private sector and professional organizations, which offer laboratories external quality assurance quality schemes in order to provide laboratories with feedback on their testing procedures, and by providing geneticists with guidelines and best practice standards. Additionally, international organizations can play a role in building consensus and developing standards, for example, by directing regulatory development and integration across international borders.
The Canadian government has declared that genetic testing/screening offered to patients should only be allowed under a doctor’s supervision. Canadian Federal and Provincial Governments are just beginning to determine the issues connected with what they consider to be an inevitable increase in the use of genetic technologies in healthcare. They are considering issues for the healthcare system as a whole, as well as for retail tests (i.e. tests available directly to the public). They foresee that the issues likely to arise include the costs, the social and ethical implications, new training requirements and the issues for insurance and employment. There are concerns about privacy issues and gene patenting. The regulation of genetic tests available through the retail market comes under the jurisdiction of the Federal Government (i.e. Health Canada) but individual provinces also have their own influence. Some tests will be available through the healthcare system in some provinces but not others, and this may lead to differential usage of retail tests in different areas. At the federal level, an expert working group has been set up by Health Canada to look at the ethical and social issues surrounding genetic testing for late onset diseases. It will provide some findings about the need to regulate genetic testing and improve assessment of the technology. At the provincial level, the government presented a report to each province and territory in Canada. The report raises concerns at the possible rise in availability of at-home tests and the potential availability of such testing via labs. It also states that Federal standards for approval and review of such at-home tests should be carefully examined and monitored to ensure that they adequately protect Canadians. The bottom line is that the government needs to ensure that genetic tests provide useful medical information and that the test results are reliable.
Conclusion:
Gene testing already has dramatically improved lives. Some tests are used to clarify a diagnosis and direct a physician toward appropriate treatments, while others allow families to avoid having children with devastating diseases or identify people at high risk for conditions that may be preventable.
While genetic testing/screening has its benefits, it also has its disadvantages. There are two good arguments that go against genetic screening. Some feel that genetic screening would lead to discrimination of those individuals, which possess "inferior" genes. Second, people fear that genetic screening will lead to reproductive decisions being based on the genetics of their child. Discrimination is a very real prospect, now that humans posses the technology to analyze genetic contents. As discussed previously, insurance companies and employers would like to be able to determine insurance rates and employment statuses based on the genetic composition of people. Individuals may be prevented from obtaining insurance due to a high risk factor for a certain disease.
Many people fear that genetic screening will change the way humans reproduce. Instead of allowing reproduction to occur naturally, people could use fetal and embryonic genetic screening in order to select for a better child. Many people would be messing with God’s creation and nature, and that humans are not meant to do this. Secondly, abortion also becomes an issue, because if the parents of an unborn child find out that their child has a certain genetic defect, they may decide to end the pregnancy. In addition, some religions consider any interference with the natural act of reproduction to be immoral. Thirdly, what would happen to individuals who were carriers for genetic abnormalities? Would they be encouraged not to reproduce? In this situation it seems as though the individual would be better off not knowing about their condition.
Bibliography: Works Cited
Christenson, Shaun . "The Ethical Considerations of Genetic Screening."NDSU - North
Dakota State University. N.p., n.d. Web. 15 Dec. 2012. <http://www.ndsu.edu/pubweb/~mcclean/plsc431/students98/christenson.htm
Devore, David. "GENETIC SCREENING AND ETHICS AN OVERVIEW." The
Woodrow Wilson National Fellowship Foundation. The Woodrow Wilson National
Fellowship Foundation, n.d. Web. 15 Dec. 2012. <http://www.woodrow.org/teachers/bi/1992/gen_screen1.html
"Genetic Testing and Screening in the Age of Genomic Medicine: Executive
Summary." Genetic Testing and Screening in the Age of Genomic Medicine. Department
of Health, n.d. Web. 15 Dec. 2012.
< http://www.health.ny.gov/regulations/task_force/reports_publications/screening.htm>.
"Gene Testing." Oak Ridge National Laboratory. U.S. Department of Energy Office of Science, 17 July 2010. Web. 15 Dec. 2012. <http://www.ornl.gov/sci/techresources/Human_Genome/medicine/genetest.shtml
"Genetic Testing." Wikipedia: The Free Encylopedia. Media Wiki and Wikipedia project, n.d. Web. 15 Dec. 2012. < http://en.wikipedia.org/wiki/Genetic_testing
by
cherno (student)
