Bioethics. Группа авторов

“imperfect” people without their consent.

      This position raises two separate issues. One pertains to the legitimacy of different views on abortion. Despite the conviction of many abortion activists to the contrary, I believe that ethically respectable views can be found on different sides of the debate, including one that sees fetuses as developing humans without any serious moral claim on continued life. There is no space here to address the details, and doing so would be once again to fall into the trap of letting the abortion question swallow up all others. However, opponents of abortion need to face the fact that many thoughtful individuals do not see fetuses as moral persons. It follows that their reasoning process, and hence the implications of their decisions, are radically different from those envisioned by opponents of prenatal screening and abortion. So where the latter see genetic abortion as murdering people who just don’t measure up, the former see it as a way to prevent the development of persons who are more likely to live miserable lives, a position consistent with a world‐view that values persons equally and holds that each deserves a high‐quality life. Some of those who object to genetic abortion appear to be oblivious to these psychological and logical facts. It follows that the nightmare scenarios they paint for us are beside the point: many people simply do not share the assumptions that make them plausible.

      How are these points relevant to my discussion? My primary concern here is to argue that conception can sometimes be morally wrong on grounds of genetic risk, although this judgment will not apply to those who accept the moral legitimacy of abortion and are willing to employ prenatal screening and selective abortion. If my case is solid, then those who oppose abortion must be especially careful not to conceive in certain cases, as they are, of course, free to follow their conscience about abortion. Those like myself who do not see abortion as murder have more ways to prevent birth.

Huntington’s Disease

      There is always some possibility that reproduction will result in a child with a serious disease or handicap. Genetic counselors can help individuals determine whether they are at unusual risk and, as the Human Genome Project rolls on, their knowledge will increase by quantum leaps. As this knowledge becomes available, I believe we ought to use it to determine whether possible children are at risk before they are conceived.

In this chapter I want to defend the thesis that it is morally wrong to reproduce when we know there is a high risk of transmitting a serious disease or defect. This thesis holds that some reproductive acts are wrong, and my argument puts the burden of proof on those who disagree with it to show why its conclusions can be overridden. Hence it denies that people should be free to reproduce mindless of the consequences.³ However, as moral argument, it should be taken as a proposal for further debate and discussion. It is not, by itself, an argument in favor of legal prohibitions of reproduction.⁴

There is a huge range of genetic diseases. Some are quickly lethal; others kill more slowly, if at all. Some are mainly physical, some mainly mental; others impair both kinds of function. Some interfere tremendously with normal functioning, others less. Some are painful, some are not. There seems to be considerable agreement that rapidly lethal diseases, especially those, such as Tay‐Sachs, accompanied by painful deterioration, should be prevented even at the cost of abortion. Conversely, there seems to be substantial agreement that relatively trivial problems, especially cosmetic ones, would not be legitimate grounds for abortion.⁵ In short, there are cases ranging from low risk of mild disease or disability to high risk of serious disease or disability. Although it is difficult to decide where the duty to refrain from procreation becomes compelling, I believe that there are some clear cases. I have chosen to focus on Huntington’s Disease to illustrate the kinds of concrete issues such decisions entail. However, the arguments are also relevant to many other genetic diseases.⁶

      The symptoms of Huntington’s Disease usually begin between the ages of 30 and 50:

Onset is insidious. Personality changes (obstinacy, moodiness, lack of initiative) frequently antedate or accompany the involuntary choreic movements. These usually appear first in the face, neck, and arms, and are jerky, irregular, and stretching in character. Contradictions of the facial muscles result in grimaces; those of the respiratory muscles, lips, and tongue lead to hesitating, explosive speech. Irregular movements of the trunk are present; the gait is shuffling and dancing. Tendon reflexes are increased…Some patients display a fatuous euphoria; others are spiteful, irascible, destructive, and violent. Paranoid reactions are common. Poverty of thought and impairment of attention, memory, and judgment occur. As the disease progresses, walking becomes impossible, swallowing difficult, and dementia profound. Suicide is not uncommon.⁷

      The illness lasts about fifteen years, terminating in death.

Huntington’s Disease is an autosomal dominant disease, meaning it is caused by a single defective gene located on a non‐sex chromosome. It is passed from one generation to the next via affected individuals. Each child of such an affected person has a 50 percent risk of inheriting the gene and thus of eventually developing the disease, even if he or she was born before the parent’s disease was evident.⁸

Until recently, Huntington’s Disease was especially problematic because most affected individuals did not know whether they had the gene for the disease until well into their child‐bearing years. So they had to decide about child‐bearing before knowing whether they could transmit the disease or not. If, in time, they did not develop symptoms of the disease, then their children could know they were not at risk for the disease. If unfortunately they did develop symptoms, then each of their children could know there was a 50 percent chance that they too had inherited the gene. In both cases, the children faced a period of prolonged anxiety as to whether they would develop the disease. Then, in the 1980s, thanks in part to an energetic campaign by Nancy Wexler, a genetic marker was found that, in certain circumstances, could tell people with a relatively high degree of probability whether or not they had the gene for the disease.⁹ Finally, in March 1993, the defective gene itself was discovered.¹⁰ Now individuals can find out whether they carry the gene for the disease, and prenatal screening can tell us whether a given fetus has inherited it. These technological developments change the moral scene substantially.

How serious are the risks involved in Huntington’s Disease? Geneticists often think a 10 percent risk is high.¹¹ But risk assessment also depends on what is at stake: the worse the possible outcome, the more undesirable an otherwise small risk seems. In medicine, as elsewhere, people may regard the same result quite differently. But for devastating diseases such as Huntington’s this part of the judgment should be unproblematic: no one wants a loved one to suffer in this way.¹²

      There may still be considerable disagreement about the acceptability of a given risk. So it would be difficult in many circumstances to say how we should respond to a particular risk. Nevertheless, there are good grounds for a conservative approach, for it is reasonable to take special precautions to avoid very bad consequences, even if the risk is small. But the possible consequences here are very bad: a child who may inherit Huntington’s Disease has a much greater than average chance of being subjected to severe and prolonged suffering. And it is one thing to risk one’s own welfare, but quite another to do so for others and without their consent.

Is this judgment about