The Controversy of Genetic Screening
Craig Ventor completed sequencing human DNA in June of 2000, accomplishing the first major endeavor of the Human Genome Project (HGP) (Ridley 2). As scientists link human characteristics to genes-segments of DNA found on one or more of the 23 human chromosomes-prospects for genetic engineering will increase dramatically. One relatively simple but powerful application of the HGP is genetic screening. By abstracting and analyzing DNA from embryos, fetuses, children or adults, one can detect the presence or absence of specific genes. While some think of genetic screening as a great scientific and medical advancement, others see it as a dangerous and frightening enterprise. With careful regulation, I believe genetic screening can affect individuals in a beneficial manner. Pre-natal genetic screening is currently used in high-risk pregnancies for detection of diseases such as Down Syndrome and Huntington's chorea (Ridley 55, 98). As scientists determine the genes for additional genetic conditions, screening of embryos will provide more information to potential parents before their fetus is fully developed. If a screened fetus were found to carry genes for a particular disease or disability, its parents may selectively abort it. Many individuals who believe in pro-choice abortion laws advocate pre-natal screening for genetic diseases because the abortion of fetuses with undesirable traits may decrease the number of unwanted children. Those against abortion strongly oppose pre-natal screening, speculating an increase in abortion rates if screening were a part of routine obstetric examination. Widespread pre-natal screening will undoubtedly lead to abortions that would have otherwise been avoided. Even pro-choice advocates disagree on the circumstances that validate abortion. There is little or no argument against the current abortion of fetuses with genes for Down Syndrome. I speculate that controversy would ensue if the abortion of fetuses with fatal but less debilitating diseases, such as diabetes, became commonplace. I propose the following question: what makes a genetic disease or disability severe enough to validate selective abortion of an affected fetus? Pernick discusses the meaning of health, indicating that an individual who is unable to complete a physical or mental task that others can do has a disability. If people with below-average IQ have low probability of obtaining jobs with above-average salaries in spite of their efforts, are they unhealthy (Lemonick 57-8)? In our society, are homosexuals considered diseased (Henry 3,6)? Is an ugly person who cannot find a mate, in a sense, disabled? The abortion of individuals who do not exhibit desirable aesthetic traits may seem extreme. However, with no laws regulating such abortions, I speculate that some would take place. Because I believe that unwanted children should not be born regardless of their health status, I do not propose laws that disallow abortions of fetuses deemed healthy by medical standards. Instead, I propose laws regulating pre-natal screening. We should only screen embryos and fetuses for 'abortion-worthy' diseases. These "abortion-worthy" diseases should be designated by a national bioethics committee not unlike the one currently headed by Kass (Gibbs). While every condition should be analyzed independently, all should have common, identifying characteristics. Genetic diseases severe enough to validate abortion are those in which the afflicted are terminally physically dependent on others to fulfill their basic life needs, regardless of the environment. By basic life needs I mean the ability to eat, drink, breath, move, and communicate as required for daily sustenance. I believe that aborting individuals who would have such diseases is valid. These guidelines for pre-natal genetic screening give prospective parents the option of aborting a child with certain diseases and/or conditions, and they prevent abortion for more trivial reasons. One disadvantage is that these policies do not allow for the dispensing of information regarding genetic predisposition for medical conditions. Scientists have discovered numerous genes related to diseases such as cancer. If individuals are going to contract a disease at around age 50, should they not know this? Genetic screening, in this sense, could alleviate the 'health guessing game.' Revealing individuals' medical future would allow them to act as they pleased, for they would already know the future of their physical condition. This picture presents genetic screening as the pinnacle and culmination of preventative medicine. In reality, the genetic model for disease is not this simple. Genetic screening is not a crystal ball that foresees an unchangeable medical future. Having genes for specific diseases does not indicate that individuals will acquire the diseases; it simply means that they have a greater than average tendency to get them. In fact, many individuals who have genes for certain conditions never exhibit related ailments (Hubbard 133). In many cases, genes must be 'switched on' by a number of environmental factors. Progression of diseases also depends on environment and personal lifestyle. The severity of heart disease depends on diet and exercise (Hubbard 79, Ridley 87). Skin cancer, while linked to genes, often results from over-exposure to UV light. Genes are not necessarily indicative of medical future, but they play an important role alongside environment. In many ways, genetic history is analogous to the history of family disease. Just as a mother should tell her child that breast cancer runs in the family, a doctor should tell a woman that breast cancer runs in her genes. Genetic screening should be used after birth to elucidate probability of acquiring genetic diseases and debilitating conditions. The interplay of genes and environment is central to the argument for genetic screening. It allows individuals to take control of their lifestyles in manners productive to their genetic predispositions. Individuals with genes that increased their probability of getting type-II diabetes could alter their diets to prevent future problems with insulin production. People with genes for anxiety could strive for low-stress lifestyles (Ridley 167). Parents of children whose screening revealed tendencies toward being overweight could put them on special diets starting at early ages. Full-scale genetic screening appears less spectacular when the social aspects of such preventative measures are analyzed. Would the girl put on a childhood diet have severe issues with body image? Would a person whose screening revealed problems with mental clarity constantly worry about the validity of his thoughts and emotions? Is it right to immerse children with 'violent genes' in special, non-violent environments (Toufexis 52-3)? If results of genetic screenings become public knowledge, genetic prejudices may arise. Questions regarding the rights of health insurance companies to obtain results of genetic screening have already been raised (Ridley 268). These questions are best avoided rather than answered. I bring us back to the issue regarding which genes should be examined in genetic screening. I suggested the regulation of pre-natal screening by examining only illnesses that prevent the afflicted from leading physically independent lives. I do not think this is a viable solution for post-natal screening for two reasons. I base the first on the multitude of genes. The human genome is composed of approximately 35,000 genes. Widespread agreement of conditions worthy of screening would be difficult if not impossible. The second reason I do not recommend determination of 'screen-worthy' genes is that individuals aware of their genetic predispositions may react in self-destructive manners. Ideally, people who know their genetic probabilities for getting diseases would alter their lifestyles to a degree that would maximize both the quantity and the quality of their lives. However, this is unlikely in all cases. Some people, forgetting the importance of environmental effects, may view the results of their genetic screen as death-sentences. Having genes for cancer or other relatively common diseases may cause them to engage in activities detrimental to themselves or others in attempt to obtain the highest quality of their seemingly stunted lives. Others may take the opposite extreme. By altering their environments to extend their longevity, they may neglect the quality of their lives. To avoid such disproportionate reactions, I advocate neither full-scale genetic screening nor general screening of common medical conditions. Instead, genetic screening should be used to compliment family histories and/or medical examinations. Individuals from families in which adult-onset diabetes is common could be screened for this disease to determine their likelihood of getting the illness. Likewise, women with fibercystic breasts could screen for breast cancer genes to determine their probability for developing malignant tumors (Hubbard 86-92). Genetic screens should be specific to diseases or conditions, and should be used only when historical or medical examinations reveal a high probability of an individuals' acquiring the diseases. If people were found to have genetic predispositions, counseling could help them establish a lifestyle to prevent or deter onset of the diseases. Genetic screening is a powerful medical tool that, if unregulated, has the potential of negatively affecting individuals and societies. However, implementation of screening guidelines could eliminate many of these destructive effects. Pre-natal screening should only test for 'abortion-worthy' diseases determined by a national or international bioethics committee. Children and adults should be screened for particular diseases or conditions when/if family medical histories or physical examinations find reason to do so. With such policies, I believe that genetic screening will beneficially revolutionize obstetric and preventative medicine.
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