John C. Fletcher 
exists? Further, eugenic experiments would clearly be more suscep- 
tible to control by special interests and governments, thus giving 
some credibility to the worst fears of those who today oppose even 
relatively primitive genetic experiments in plants and animals. 
Protests about the difficulty of linedrawing should be heard in the 
context of an early stage in the evolution of ethical issues in gene 
technology. Why should drawing lines be inherently more difficult 
in applied human genetics than in any other moral labor societies 
have undertaken? Genetics must not be mystified or treated differ- 
ently from any other branch of science and medicine. 
The conclusion that germline gene therapy in humans should be 
banned is also based upon a faulty premise. Again, a particular experi- 
ment is defined as the moral problem accompanied by exaggeration 
of the danger of current animal experiments to societal values. The 
proposal for a ban directed to the Senate draws a line between 
somatic cell therapy and germline research. A better line is between 
curative or preventive gene therapy and eugenic uses of germ cell 
alteration. 
Bernard Davis (1983) discussed the objection to germline experi- 
ments based upon the criticism of irreversible changes in the gene 
pool. He used as an example the desirability of germline therapy in 
Tay-Sachs disease, but his argument could also apply to any other 
serious recessive disorder. Each available option has evolutionary 
consequences. But which option has the most favorable conse- 
quences for the affected families and society? The carrier of one 
gene for the disease inherits one recessive gene from a parent in 
exactly half of all pregnancies involving carriers. Today, prenatal 
diagnosis and abortion can prevent the birth of affected infants, but 
since parents are encouraged to use this method, more carriers will 
gradually be born, increasing the number of harmful genes for the 
disorder in the population. If somatic cell therapy were possible, 
affected infants could be treated but with the consequence of more 
harmful genes in the population. Therapy in the germline could both 
prevent the disease in the person and reduce the incidence of harmful 
genes. In short, the same reasoning that supports somatic cell experi- 
ments also supports germline experiments in humans, assuming that 
all other questions about inheritable harms had been answered in 
prior animal research. The issue of inheritability of mistakes poses 
a crucial, morally relevant difference between somatic cell and 
germline experiments. This difference itself ought to demarcate 
sharply germline experiments. No plans for germline experiments 
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Recombinant DNA Research, Volume 12 
