W. FRENCH ANDERSON 
HUMAN GENE THERAPY: SCIENTIFIC AND ETHICAL 
CONSIDERATIONS 
ABSTRACT. The term ‘gene therapy’ encompasses at least four types of applica- 
tion of genetic engineering for the insertion of genes into humans. The scientific 
requirements and the ethical issues associated with each type arc discussed. 
Somatic cell gene therapy is technically the simplest and ethically the least 
controversial. The First clinical trials will probably be undertaken within the 
next year. Germ line gene therapy will require major advances in our present 
knowledge and it raises ethical issues that are now being debated. In order to 
provide guidelines for determining when germ line gene therapy would be ethical, 
the author presents three criteria which should be satisfied prior to the time that 
a clinical protocol is attempted in humans. Enhancement genetic engineering 
presents significant, and troubling, ethical concerns. Except where this type of 
therapy can be justified on the grounds of pseventive medicine, enhancement 
engineering should not be performed. The fourth type, eugenic genetic engineer- 
ing, is impossible at present and will probably remain so for the foreseeable 
future, despite the widespread media attention it has received. 
Key Words : genetic engineering, somatic cells, germ cells, enhancement, eugenics, 
humanhood. 
There are four potential levels of the application of genetic engineer- 
ing for the insertion of a gene into a human being (Anderson, 1982): 
(1) Somatic cell gene therapy: this would' result in correcting a 
genetic defect in the somatic (i.e., body) cells of a patient, 
(2) Germ line gene therapy: this would require the insertion of 
the gene into the reproductive tissue of the patient in such a way 
that the disorder in his or her offspring would also be corrected. 
(3) Enhancement genetic engineering: this would involve the 
insertion of a gene to try to ‘enhance’ a known characteristic; for 
W. French Anderson, M.D., Chief, Laboratory of Molecular Hematology, National Heart, 
Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20205, U.S.A. 
The Journal of Medicine and Philosophy 10 (1985) 275-291. 0360-5310/85.10 
© 1985 by D. Reidel Publishing Company. 
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Recombinant DNA Research, Volume 12 
