CLONING, GENE THERAPY, AND THE COMING MEDICAL REVOLUTION
As he chats with the young mother, the doctor flicks a cotton swab into the mouth of her infant son, he inserts the sample into a machine, which extracs DNA from the mucus cells and compares it with the genetic material on a dime – size chip. Minutes later a computer printer begins to spit out a list of the infant’s genes. Fortunately, all but a few of the genes are labeled “normal”. It is those few that the doctor discusses as he explains the result to the mother. “You son’s genetic inheritance is generally good, “ he says, “but he is somewhat predisposed to skin lesions. So starting right away; he should be protected againts excessive exposure to the sun. “and the doctor warns, “he may well be susceptible to cardiovascular disease later in life. To lessen his risk, after about age two he should be lifelong low – fat, high – fiber diet.”
Jaroff, 1663, p.24)
This view of a visit to a pediatrician’s office is not so futuristic, for it could become reality within the next few decades. Our increasing understanding of genetics is leading not only to the identification of risk factors in children, but also to the development of new treatments for everything from serious physical illneses, such as cancer, to psychologycal disorder like schizophrenia and depression.
This potential medical revolution has been heralded, in part, by unlikely achievement : the birth of Dolly, a rather ordinary looking sheep with an extraordinary genetic background. Doly was the first animal to be cloned from the cells of an adult sheep, making her an exact genetic replica of her “parent”. Dolly was soon followed by a managerie of cloned animals, each genetically identical to another member of its species (Pennisi, 1997c, Kolata 1998).
The ability of scientists to produce clones raises new possibilities of correcting genetic flaws, not only in sheep and other animals, but in humans, and it accelerates the pace of developments in the new field of gene therapy. In gene therapy, genes are introduced into existing cells in order to prevent or cure a disorder. For istance, genes targeted to treat a particular disease can be injected into a patient’s blood stream. When the genes reach the site of the problem such as cancerous tumor the new genes provide existing cells with a set of new instructions that modify their functioning, thereby potentially curing the disease. It also might be possible to “harvest”. Defective cells from a child prior to birth. These cells could be treated by gene therapy and reintroduced into the unborn child, thereby repairing the defect (Kmiec, 1999; Levy, 2000; Yan, Kinzler, et Vogelstein, 2000)
Some forms of gene therapy are already in use, and the number of disease treated by gene therapy is growing. For example, such disorder as AIDS, cystic fibrosis, and rheumatoid arthitis are promising candidates for gene therapy (Weiner, 2000).
Cloning advance are likely to continye to raise significant ethical issues. In one radical posibility, cloning might be employed if both a husband and wife were infertile. In such a case, they might consider cloning one or the other of themselves in order to have at least one child who was genetically similar ( in this case, genetically identical) to on eof them. The ethical and moral issues of such a procedure, of course, are profound but the rapid advances in cloning and gene therapy suggest they need to be dealt with now (Angier, 1999; Gordon 1999, Shiels et al, 1999; Wright, 1999).
Would you choose to be genetically tested so that you could know your susceptibility to future genetic disease? What if you learned that you had a genetic disorder that was likely to shorten your life?
