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Genetics, neuroscience, and biotechnology.

Genetics, Neuroscience, and Biotechnology

Three areas of biomedicine pose dramatic dilemmas for bioethics. While medical ethicists will continue to grapple with the issues posed by the unrelenting problems of treating AIDS and cancer patients, new developments in genetics, neurobiology, and biotechnology will generate novel ethical questions.

In genetics, the Human Genome Project will generate new data about the biological underpinnings of human attributes and proclivities to wellness and disease. Originally designed to uncover the DNA base sequence of the entire 100,000 or so genes embedded in human DNA, it has recently been scaled back to a mapping project including sequence analysis of nucleotide bases surrounding certain limited "hot spots." Even in its scaled-down version, the genome project raises major issues of distributive justice. By its price alone (budgeted at $109 million for 1991-92), it threatens to displace equally worthy endeavors in basic research. A good discussion of this issue is found in a recent perspectives piece by Bernard D. Davis et al., "The Human Genome and Other Initiatives," Science 249 (1990), 342-43.

Once the data from the genome project begins to be assembled it will present distributive questions of its own. Which disorders are sufficiently serious and prevalent to deserve the earliest attention? Which genetic tests should be pressed into service in screening operations? What groups of persons--extended families, ethnic groups or lineages--deserve priority for investigation? Even these earliest findings will raise potential problems of privacy, confidentiality, and applicability; see "Ethics and the New Genetics," Lancet 335 (1989), 1054-55. Insurers and health maintenance organizations may demand access to personally identifiable genetic information. When should data that indicate a modest probability of future disability or proclivity to disease (for example, susceptibility to infection with HIV) be used? What is the demarcation point of certainty that warrants use of linkage data to indicate readiness of a new gene probe for marketing? This last dilemma has confronted cystic fibrosis researchers intent on developing a diagnostic test, as reported by Leslie Roberts, "CF Screening Delayed for Awhile, Perhaps Forever," Science 247 (1990), 1296-97, since the genetic mutations for cystic fibrosis have turned out to be much more complex than initially thought.

To date, major insurers and underwriters have been reluctant to put genetic data into their testing requirements. Major employers are similarly hesitant about using susceptibility markers to screen workers in hazardous settings where toxic exposures may occur. This reluctance raises ethical questions of its own. If we can predict who is at high risk for heart disease, lung cancer, and bladder cancer from simple genetic tests, do we not have an obligation to make such tests widely available (assuming their high predictive value)? And what about the insurer's position that it has traditionally exercised the right to identify, exclude, or underwrite individuals commensurate to their risk status? These questions are examined in "Insurance Costs and Genetic Testing," Lancet 335 (1990), 1331.

The genome project will undoubtedly identify genetic data of potentially great diagnostic value. Within the confines of the doctor-patient relationship, it is unlikely that this information will pose major difficulties. However, genetic data almost always has relevance outside the domain of this relationship, implicating members of a kindred group as carriers, likewise affected, or at risk for similar disorders. Walther C. Zimmerli explores this in "Who Has the Right to Know the Genetic Constitution of a Particular Person?" Ciba Foundation Symposium 149 (1990), 93-102. How and when should such persons be notified of their possible risk status? Sometimes, as has proven to be true for the multiple genetic mutations that cause cystic fibrosis or neurofibromatosis, the genetic data make these issues even more complex. Elsewhere, as with Huntington's disease, final confirmation of risk status may require testing of relatives, some of whom may not wish to know their own status. And clinicians may be reluctant to perform presymptomatic tests on children who cannot give informed consent, or whose test results may be ambiguous, a problem explored by D. Craufurd and colleagues in "Testing of Children for 'Adult' Genetic Diseases," Lancet 335 (1990), 1406.

When used in prenatal diagnosis or embryo selection the data from newly developed gene probes can be a boon or a dilemma. Sex selection or early embryo testing ("preimplantation testing"), where a polar body or single cell can be assayed for the genetic status of a yet-to-be implanted embryo, raise the specter of a Brave New World of eugenics even as they afford couples new opportunities for avoiding genetic disease in their offspring. These issues were debated at the first Preimplantation Testing Conference, held at the Illinois Masonic Hospital in Chicago on 19-21 September 1990.

In the neurosciences, equally farranging developments promise to decipher the neuronal basis for perception and some forms of cognition and memory. Receptors for bioactive molecules that control pain, mood, and rage are also being uncovered. These developments, like the newly uncovered receptor sites for tetrahydro cannabinol (discussed by Timothy M. Beardsley, "Cannabis Comprehended," Scientific American 263 [1990], 38), promise to open avenues for new analgesic, antiemetic, or mind-altering drugs.

Chronic neuropathic conditions like Alzheimer's disease may soon prove amenable to experimental intervention; see Jeffrey C. Cummings and Bruce L. Miller, "Alzheimer's Disease: Long-Term Management," Lancet 335 (1990), 260-64. How to proceed in developing such therapies will require guidelines for testing borderline competent adults.

Other problems will come with the uncovery of the neurologic basis for certain forms of thought disorders, compulsive behaviors, or neuroses. Therapies for extreme forms of such disorders may lead to wider uses of potent drugs in conditions of borderline pathology, as occurred with the benzodiazepine group of tranquilizers (see R. S. Jones, "Patient Involvement in Benzodiazepine Withdrawal," Lancet 335 [1990], 61-63). Setting limits to the use of such drugs will be a major priority for the bioethical and medical communities.

This problem has already surfaced for some of the modalities of treatment developed through biotechnology. Human growth hormone, originally developed for the limited treatment of HgH deficient children with forms of pituitary dwarfism, has found questionable application in short-stature children and athletes in search of a nondetectable anabolic steroid. Most recently, its use to offset some of the deterioration in muscle mass which occurs with aging raises the specter of further unapproved use. Recent discussions of these issues can be found in Gian Luigi Spadoni et al., "How Far Should Indications for Growth Hormone Expand?" Lancet 335 (1990), 1351; and David B. Allen and Norman C. Fost, "Growth Hormone Therapy for Short Stature: Panacea or Pandora's Box?" Journal of Pediatrics 117:1 (1990), 16-21.

Ethical guidelines may also prove desirable for erythropoietin, a red-blood-cell-stimulating hormone widely used for treating anemia in kidney dialysis patients (see Katarina Rosenlof et al., "Treatment with Erythropoietin in Haemodialysis," Lancet 335 [1990], 247-49). Its use as a doping agent for athletes intent on improving performance is but another example of how extremely potent hormones and cytokines can be misused. The common denominator for all such products is their extraordinary biological activity in very small doses plus their high cost. When and how to use them in medical situations is resolvable through traditional experimental testing programs. But how and when to underwrite the cost of their initial development (e.g., through invocation of the Orphan Drug Act) and how to limit the possibilities of illicit or unapproved uses is problematical.

Clearly, guidelines that spell out the limits of experimental therapies are needed in these areas as they are in developing novel AIDS treatments. If we are to avoid wasting precious resources on therapies looking for diseases to treat (as may be the case for interleukin-2, a lymphokine developed for treating kidney cancer), we need clearer guidelines of what constitutes an indication for therapy and how much society is willing to invest in underwriting treatments for rare disorders, or unproven remedies for treating common ones.

The major ethical issues raised by all of these developments may require a shift from an individual-oriented ethics that emphasizes autonomy and protection of single persons to a collective, community ethic that recognizes the primacy of distributive justice. In its later stages, the knowledge from the genome project will affect society generally, raising new issues of civil liberties and the public good. Neurobiological developments will find collective application in drugs or therapies that can influence learning or retard the aging process. In biotechnology, extremely potent biomolecules will find their way into large-scale production, opening avenues for assisting underserved populations or becoming new drugs of abuse for the well-to-do.

These developments raise questions that transcend individual ethics. Their resolution calls for nothing less than a recommitment of bioethics to the goal of defining both the common good and the best means of attaining it.

Marc Lappe is professor of health policy and ethics, Department of Medical Education, College of Medicine, University of Illinois at Chicago.
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Title Annotation:The Best of Bioethics; discussions in recent journal articles
Author:Lappe, Marc
Publication:The Hastings Center Report
Article Type:bibliography
Date:Nov 1, 1990
Previous Article:Common-sense morality.
Next Article:Still saving the life of ethics.

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