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Genetic screening is a pressing issue in today's public policy forum, research and industry. Genetic screening provides enormous opportunities and is an incredible advance in science. However, genetic screening poses problems that are not and can not be easily overlooked. These are the following two issues dealt with in this paper. What can genetic screening offer people that currently is not being offered and at what cost to the people will this advance be? Genetic screening was devised to offer people a service and more important, to essentially, protect them from themselves.
Genetic screening involves the screening of persons' genotypes to determine if they (1) are already associated with disease or are predisposed to disease, (2) may pass on disease to their descendants, or (3) produce other variations not associated with disease. (NAS 1975) Genetic screening is used as a means to prevent the onset or provide control for genetically inherited diseases. This in the long run is economical and treatment is effective.
Screening of this type involves the detection of genetic disease and must first be defined to assure an understanding in the objectives of screening. Carriers of a genetic disease appear normal and are not affected except if the trait is expressed quantitatively across a population. In this case, the individual will have some disease characteristics however, not as severe as those with the disease. Individuals that have a genetic disease are almost always homozygous recessive for that gene meaning that there is an insufficiency in its ability to perform the correct function.
One must not mistake a genetic screening test with a genetic diagnostic test. The difference is great and can be easily confused. A genetic screening test is not a definite confirmation of disease presence. It only gives an alert or signal to the possible presence that could affect the health of an individual. A genetic diagnostic test can tell with greater certainty if a disease is present in an individual. (Blatt 1996)
There are different times throughout the life span of a human in which genetic tests, both screening and diagnostic, can be preformed. The most popular and recognizable are the prenatal tests and testing of newborns. The genetic screening tests currently available for pregnant women are maternal serum alpha-fetoprotein (MSAFP) screening, enhanced MSAFP, amniocentesis, chorionic villus sampling (CVS), percutaneous umbilical blood sampling (PUBS), fetal biopsy and fetal cell sorting. (Blatt 1996)
MSAFP is a blood-screening test performed at the 16-18 week gestation date and tests for spina bifida. Enhanced MSAFP is also a blood-screening test that measures levels of certain biochemical markers to test for the presence of Down's syndrome. However, this test only has an accuracy of 60-65%. (Blatt 1996) Amniocentesis performed at the 16-18 week of gestation uses amniotic fluid to test for chromosomal abnormalities. It can also be used to find biochemical abnormalities at the genetic level, detecting up to 180 genetic disorders. CVS is performed 10-12 weeks into gestation and uses chorion tissue for chromosomal analysis in biochemical and DNA studies. This test is not widely used because of correlation to producing newborns with limb abnormalities. PUBS can be performed after week 18 and is used only as a confirmation test based on results from previous tests. Fetal biopsy involves taking fetal tissue for DNA testing. Fetal cell sorting is an experimental procedure that takes blood from the mother and tests the fetal cells in the mother's blood. (Blatt 1996)
All 50 states and the District of Columbia require by law the administration of genetic screening tests on all newborns. The two tests required screen for phenylketonuria (PKU) and congenital hypothyroidism. (The Gene Letter 1996) In addition, 43 states and D.C. screen for galactosemia, and forty-two states and D.C. screen for sickle cell disease. Some states screen for maple syrup urine disease, hemocystinuria, biotinidase deficiency and other rare disorders. (The Gene Letter 1996) Nearly all the preceding diseases, if dealt with immediately, can be treated and the individual can lead a normal life. However, if not detected within days of birth the individual will become mentally retarded and may soon die after birth. As one can see, genetic screening for these conditions is necessary and of great service to the people.
Genetic screening tests are used to identify carriers of specific diseases. Those tests screen for sickle-cell anemia in Blacks, Tay-Sachs in Jewish persons from Eastern Europe descent, and thalassemia in people of Mediterranean and Southeast Asian origin. (Blatt 1996) Carrier tests are also performed on women to identify genes carried on the X chromosome most commonly known as sex-linked traits/diseases such as hemophilia. Recent research and identification of the cystic fibrosis gene has lead to genetic screening of suspected carriers. (Blatt 1996). Even though errors in the genetic code that lead to metabolic deficiencies are rare in that only 1/10,000 newborns are born with a genetic metabolic disorder, the frequency of being a carrier is 1/1,000 leading to significant probabilities of producing affected children with another carrier. (NAS 1975)
Premarital screening is another form of genetic screening but is not common in our population as a whole. Screening of this nature has been limited to certain religious and ethical groups. Currently, there is a database for Tay-Sachs screening results in the New York City area for the Jewish people. (Blatt 1996) This is being done to avoid a match of two carriers. There may be many other databases in the future once the Human Genome Project identifies with great certainty genes linked to disease.
Genetic screening tests also include presymptomatic genetic testing. These tests primarily focus on single-gene conditions, such as Huntington's disease, and are used in families that are known to be at high risk. Just recently, the BRCA1 gene, known to cause cancer in women, can be detected through presymptomatic genetic testing. (Blatt 1996) However great the abilities of technology to determine the future, social and psychological problems do exist. Do we really want to know what our genetics has planned for us?
Genetic screening is used for many reasons that includes screening for management; screening to provide reproductive information; screening for enumeration and screening for research. These are considered the "acceptable" forms of screening. (NAS 1975) However, a problem arises when persons are forced to become a genetic screening patient.
Currently, drug testing in the work place is common procedure. This procedure is under pressure because of the legality of test administration, implications of test results and constitutional guarantees. In the future, employers may have the right to perform not only drug tests but also genetic tests screening for certain genes that may lead to a disease that will bear great costs on the employer. Like drug testing, genetic testing has many social and ethical disputes.
Supporters of genetic screening in the workplace claim that not only would the employer benefit but also the employees and society as a whole. According to one report, 390,000 workers contract disabling occupation diseases each year with 100,000 of these workers dying. (Issues in Ethics v.4, n.2) Employees would benefit from genetic screening because they would have knowledge of their genetic status and would avoid environments that act as catalysis to degrade their health thus affecting them emotionally, physically and financially. Employers would be the obvious benefactors. They would be able to select workers with "clean" genetic records thus saving them money in insurance premiums, absenteeism, lower productivity and liability. Society would benefit because of reduction in health care costs.
Supporters agree that the employee must be protected and those that choose not to have a genetic test would not be forced to. However, they would have to find employment at another location that wouldn't require genetic testing. So, is the employee really being protected or just given an ultimatum that if you don't submit to a test then they must leave the company and seek out employment somewhere else. This may be okay if only few companies participate in genetic screening procedures, but if large proportions of the companies are requiring testing then where does the employee go.
Those opposed to genetic screening in the work place argue that it is unjust to screen workers and hire based on genetic traits instead of knowledge, experience and skills. They argue that one can not control their genetic makeup just as they can not control sex or race and should therefore not be discriminated. They say that genetic testing would compound discrimination because many genetic diseases are associated with sex or race. For example, the trait for sickle-cell anemia is found in 1 out of 12 blacks, but only 1 out of 1000 whites. (Issues in Ethics v.4, n.2) This would result in victimizing those that have been victims of discrimination in the past. Opponents to genetic screening also argue that the validity and reliability are not certain enough with inaccuracy in the results. Another problem is that there is no definite understanding between the relationship of genetic traits and the chance of disease development in the future. Even with complete accuracy in finding the presence of a genetic trait, there is no absolute positive prediction that an individual will actually ever be inflicted with the disease. There would be an automatic labeling of these individuals as "mutant" or "defective" making it a difficult task to find employment. And because genetic diseases are inherited their descendents could become victims and therefore, create a class of "defective" people in society. They argue that the employee is at no gains if they know the results of genetic tests. If fact, they feel if individuals know they have a chance of becoming ill with Huntington's Disease then the psychological damage would be tremendous and irreversible.
Screening to provide reproductive information tests individuals who may be carriers of genetic disease to determine the probability that their offspring may be inflicted with disease. This can also be done via amniocentesis to determine it the fetus has a condition that causes abnormalities. This is often done in older, pregnant women because of the high probability of producing a child with Down's Syndrome. However, if the results are positive (genetic trait is present), then a difficult decision must be made between the parents.
Screening for enumeration is done for the basis of statistics and correlation for public health services. Officials take into account many factors such as environmental conditions, weather patterns and individual conditions when determining relevance of figures. If they notice high numbers of abnormalities among babies in certain areas that have the same conditions conclusions as to why it happened can be made. This is often seen among certain kinds of drugs that trigger defects or death among certain groups of people.
There are two purposes in screening research. One is to test hypotheses related to human physiology and evolution but not necessarily to health or disease. (NAS 1975) The second investigates the feasibility of screening for service. They test new methods and procedures, and molecular markers to determine which ones are useful in genetic screening.
Genetic screening within the last two years is widely known for the use of DNA analysis in criminal cases. Since 1987, the first use of DNA analysis in the United States, 24,000 cases have involved DNA evidence. (Begley et al. 1994) In the most public and widely known case in judicial history, the State of California used DNA screening results as their main element in prosecuting O.J. Simpson. This case brought the importance, use and procedure to the public's eye, and even brought humor into genetic screening making David Letterman's Top 10 List. Regardless of the case outcome, it is known that the biggest concern of the defense was the DNA test results linking O.J. Simpson, without a doubt (1 out of 21 billion), to the murders of Nicole Brown Simpson and Ronald Goldman. (Court TV 1995) They made attempts to (1) withhold the results as evidence in the case, (2) argue validity of the results and (3) suggest blood tampering, procedural error and human error in collection. The defense was successful in suggesting and convincing jurors that blood samples were tampered with and error occurred in collection thus rejecting probabilities of matching proposed by The State.
Most recently, former NBC sportscaster Marv Albert's DNA results from the bite on the back of his victim matched DNA patterns found in his blood. The chance that it could have come from someone else was 1-in-2.6 billion. (Court TV 1997) Perhaps this result was the biggest blow in the prosecution's case and possibly the reason behind plea-bargaining. So, one can see that DNA screening is becoming an important use in the judicial system. Don't be surprised if in the future if there are more plea bargains and old crimes opened up because of allowing DNA screening results as evidence.
Within the last few weeks, the FBI has concluded that DNA screening is so certain of matching an individual to a sample that the odds can be one in a trillion that it could have come from someone else. Under a new policy that started October 1, 1997 for FBI expert witness, if the probability exceeds one in 260 billion then it will be used as identification in testimony. (CNN 1997)
Ideally doctors and researchers in medicine would like to develop antidotes for all diseases. However, to do this is nearly impossible. Strains of bacteria, viruses and other disease causing agents are getting tougher. There are known bacteria strains, to which there is no antibiotic. There are obvious viruses that have either no vaccine or no cure after the onset. And with industry, genetics and environmental agents there are many diseases developed that can not be cured or even controlled.
It is the job of science, if possible, to develop a vaccine or identify precursors that can take care of disease before it strikes. This is the ideal situation. With genetic screening, many genes associated with diseases have been identified by chromosome location. Therefore, we can determine persons that may have high probabilities of disease or the onset of other characteristics associated with disease. With this we can have preventative medicine, one objective of genetic screening.
Many argue that it is unethical and inhumane to screen persons for disease when there is not a known cure. Treatment of individuals in the past has occurred when the molecular mechanisms of the drugs were not entirely understood. Let screening and treatment of genetic disorders begin while cures are being developed. To withhold this from the public would be unjust to not provide a much-needed service.
Many also argue that it is unethical to implement large screening programs because it infringes on human rights. During the last 20 years, more than 1 million Jews have voluntarily screened for Tay-Sachs. The number of children born with Tay-Sachs has, in many communities, decreased ten-fold. (Stawicki 1995) These numbers are obvious to the success of the program.
Another argument against genetic screening is that it could lead to discrimination based on genetics. Discrimination results from public ignorance and fear. This could be facilitated with education and creating programs that are accessible. Just as the confidentiality of our medical records are protected genetic screening test results could also be protected. It only makes sense.
Arguably, the greatest fear of genetic discrimination results from insurance companies denying coverage to people at risk. As unfortunate as this is, the truth is that it only makes economic sense. Genetic discrimination wouldn't even be a concern, let alone the biggest concern, if there was a public health care system that took care of its people. Genetic screeners only want to provide prevention and healing to our public and offer this as a service. With public health care, I believe only then can genetic screening provide a true service, as intended and develop for, to the people of America with all having equal opportunity just as Title VII of the Civil Rights Act of 1964 currently guarantees us.
Begley, Sharon, et al. "Blood, Hair and Heredity." Newsweek 11 July 1994: 24-25.
Blatt, Robin JR. "An Overview of Genetic Screening and Diagnostic Tests in Health Care." Obtained from the WWW: http://www.geneletter.org/0996/screening.htm
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Kevles, Daniel J. and Leroy Hood, eds. The Code of Codes. Cambridge: Harvard University Press, 1992.
Letterman, David. "Signs of Sloppiness in the L.A.P.D. Crime Lab." Obtained from the WWW: http://www.cbs.com/latenight/lateshow/top10/lists/950807.html
Morris, Jane. "Marv Albert's DNA Test Results." Obtained from the WWW: http://www.courttv.com/casefiles/marv/marv.html
National Academy of Sciences. Genetic Screening: Programs, Principles and Research. Washington, D.C., 1975.
"Newborn Screening to Prevent Mental Retardation." Obtained from the WWW: http://www.TheArc.org/faqs/nwbrnqa.html
"Read My Genes: Genetic Screening in the Workplace." Obtained from the WWW: http://www.scu.edu/Ethics/publications/iiev/v4n2/genes.shtml
Roberts, L. 1990. "To test or not to test?" Science 247:17-19.
Stawicki, Scott. "Pros of Genetic Screening." Obtained from the WWW: http://biology.uoregon.edu/Biology_WWW/Biospheres/winter95/Genetics/G.ScreenPros.html
"Week by Week in the O.J. Simpson Criminal Trial." Obtained from the WWW: http://www.courttv.com/casefiles/simpson/criminal/summary/week16.html
"Week by Week in the O.J. Simpson Criminal Trial." Obtained from the WWW: http://www.courttv.com/casefiles/simpson/criminal/summary/week17.html
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