The Ethical Considerations of Genetic Screening
Ever since Watson and Crick deciphered the biological code of life, scientists have been busy unraveling the mysteries of life. A recent development in the area of genetic research has been the Human Genome Project (HGP). The HGP is a massive international effort to map and sequence the entire human genetic code. The primary goal of this research is to link certain diseases with abnormal genes that may be possessed by certain people. This would allow researchers the ability to screen individuals for certain diseases. This has already been a success with a number of conditions. PKU is a condition that causes severe retardation in children if nothing is done to prevent it, but by genetically screening the infants, doctors are able to tell who has the disease (Davis 1990). By simply altering the diet of these children, the mental retardation effects of the disease can be prevented. In addition, diseases such as Huntington’s disease, breast cancer, and muscular dystrophy are presently being screened for in humans (Jaroff, 1996).
How researchers are able to screen for genes
New developments have given researchers the ability to decipher the genetic code of organisms. Some of the techniques that researchers use are RFLP (restriction fragment length polymorphism) analysis and DNA probes.
RFLP analysis utilizes enzymes from bacteria that are thought to be used as defense mechanisms against invading viral DNA. The enzymes fragment foreign DNA at specific locations depending on the base sequence (Griffiths, 1996). In order to analyze an organism’s genome a researcher will add a certain restriction enzyme to DNA. This produces small restriction fragments of DNA that vary in length. Electrophoresis is then used to separate out the various fragments of DNA. This is accomplished by subjecting the fragmented DNA to an electrical charge after it has been placed onto an agarose gel plate. Due to differences in length, the DNA restriction fragments will be separated in the gel plate.
Another useful tool for scientists has been the DNA probe. A DNA probe is a piece of DNA that binds to certain sequences of the hosts DNA (Devore, 1998). The probe is able to do this because the DNA strand of the probe only binds to the appropriate DNA with a complementary sequence. Scientists label the probe with florescent markers or radioactive markers so that the gene of interest can be visualized. Often probes are used in conjunction with RFLP. After the organisms genome has been fragmented and electrophoresed, an absorbent membrane is placed over the gel and the DNA bands are "blotted" onto the membrane (this technique is called Southern Blotting). The membrane is then exposed to a labeled probe. The probe will then hybridize to the DNA segments that contain the complementary sequences. Since the probe is labeled, the researcher is able to visualize the DNA fragments that were produced from the restriction enzymes. When the probe is bound to the restriction fragment a band is formed on the membrane. Scientists can then analyze the bands and determine the genetic composition of an individual.
The ability of scientists to screen humans for certain genetic abnormalities has led to four situations in which the ethics of genetic screening come into play. They are embryo and fetal screening, neonatal screening, carrier screening, and testing for economic reasons.
Embryo and fetal screening
A natural instinct in all parents is to have perfect children. All parents would like to have children that are free from diseases. This has led to screening of children before they are born. Fetal screening involves taking tissues from a fetus inside the mother’s womb and screening the fetal tissues for genetic abnormalities. Some of the abnormalities that are tested for are PKU, down’s syndrome, and turner syndrome. The first condition, PKU, is tested for because early detection and treatment prevent the onset of sever retardation in children positive for PKU. The other syndromes are screened for in order to allow the parent to accept the fact that their child may not be normal.
The advent of in vitro fertilization has had a tremendous impact on fetal screening. In vitro fertilization technology allows doctors to fertilize a human egg outside the mother. Cells from the early zygote can then be pulled off and screened for certain genetic abnormalities. Parents now have the ability to have multiple eggs fertilized and have each one screened for abnormalities. The parents can then choose which zygotes they would like to have implanted into the uterus. This can be viewed as a form of eugenics.
Neonatal screening is similar to fetal screening in that the purpose is to identify genetic abnormalities in which an early treatment could prevent the symptoms of the disease. PKU is again a good example for what doctors are looking for. Neonatal screening is also done in order to confirm diagnosis in children such as down’s syndrome and turner syndrome.
Screening people to determine if they are a carrier for certain genetic defects. One of the genes that is important in this instance is the gene that codes for Cystic Fibrosis. People would want to know if they were a carrier for this gene in case they were planning to have a child. If a couple found out that they were both carriers, then they would have to weigh the risks for themselves. Do we want to take the risk of bringing a child with a devastating disease into this world?
Testing for economic reasons
Testing for economic reasons is different from the previous subjects in that it would not benefit the individual in any way. This would be genetic information that would be used by insurance companies and employers in order to make a profit. Insurance companies would like to have the ability to screen customers in order to determine their dispositions for certain diseases. They then could charge the individual with a high risk an inflated premium or deny them entirely. Employers would use genetic information to determine which workers would suit their jobs.
Arguments against genetic screening
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. In addition, some diseases such as sickle-cell anemia are predominant among those who are of African American heritage and therefore could lead to racism (Reich, 1995).
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 that 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. In the Roman Catholic view, any act of reproduction that is not performed by the natural way as immoral (Smith, 1989). 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.
Arguments for genetic screening
The first argument is that by screening for genetic abnormalities, a doctor can prescribe an early treatment that would allow the person to live a longer more productive life. If an individual was found to be positive for a cancer-causing gene, then the individual could modify their behaviors in order to prevent the expression of the gene. There is an argument that an individual would probably not want to know if they were predisposed for a condition that was untreatable. This may be true, but on the other hand, if an individual knows their fate they would be able to make adjustments in their life in order to deal with their condition rather than learning about their condition later on in life. In the case of cystic fibrosis, which is chronic and incurable, the number of patients screened for this disease has risen from 9,000 in 199 to 63,000 in 1992 (Grace, 1997). Therefore people must want to know their fates if the rate of screening for an incurable disease are going up.
The obvious argument here is the wonders it could do for medicine. The procedure that will probably follow genetic screening will probably be genetic engineering. Mayeux and Schupf state that, "Molecular genetics promises a greater and more precise understanding of how genetic factors influence disease." (1995). By linking genes to diseases scientists will be able to develop treatments for diseases. The genetic knowledge of the disease process will create a revolution in how medicine is performed.
The main theme that many of the people whom are against genetic screening is that "some things man was not meant to know." However, in my view this is a very narrow minded approach to the situation. A look at the past can explain why this view may not be credible. 450 years ago it was thought of as sick, repugnant, and sinful to dissect a human cadaver (Shinn, 1996). Today this procedure is generally accepted. Think of what state our medicine would be in if someone had not taken up this practice. Our understanding of human physiology would be greatly lacking. Galileo was thrown in jail and forced to recant for his sins because he discovered that the earth was not the center of the universe. Today we accept this idea as a universal truth.
I believe that unreasonable fears have gripped those who are opposed to the use of genetic screening. Knowledge about genetics will be a great tool of the future and will lead to the elimination of numerous diseases. In the beginning, people were afraid that automobiles were a creation of the devil. Today, people accept travel by car as totally normal and most of the people in the United States feel that ownership of a car is a necessity. We do not look at the negative sides of car ownership. The fact that we create pollution buy driving our cars, or that thousands of people die each year in auto accidents. Instead we tend to think about the positive aspects of what car ownership does for us. New developments will probably always unsettle people because it presents people with a new way to look at themselves and the world around them, but after time people accept these changes. Genetic screening will probably present a similar scenario. Fear will be present in the beginning, but as time passes people will begin to accept genetic screening as a norm and will see it as a benefit to society, even if some of the effects of it are negative.
There are certain protections that will have to be provided for people though. A fear that many people have is that insurance companies and employers will be able to obtain your genetic information and deny health insurance or employment due to genetic dispositions of an individual. This definitely needs to be prevented. Already state governments are instituting laws against employers and insurance companies using genetic information for employment or insurance purposes (Hudson et al., 1998). This is definitely a step in the right direction.
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