Ethics for a Brave New World, Second Edition by John S. Feinberg & Paul D. Feinberg

Author:John S. Feinberg & Paul D. Feinberg [John S. Feinberg and Paul D. Feinberg]
Language: eng
Format: epub
ISBN: 978-1-4335-2646-6
Publisher: CrossWay
Published: 1993-03-21T16:00:00+00:00

CHAPTER ELEVEN

GENETIC ENGINEERING AND GENES

Alzheimer’s Disease is a degenerative brain disorder characterized by a relentless loss of brain cells. It is accompanied by a gradual loss of memory and the ability to reason. Those who have it eventually become seriously disoriented, cannot care for themselves, and die. What if this terrible disease were controlled by one’s genes and scientists could correct those genes so that those at risk would neither get the disease nor pass the defective genes to their children?

Early in 1991, researchers found two defective genes related to Alzheimer’s and expected to find soon a third gene involved. Such discoveries give hope for eventually finding a cure.1

Despite the positive potential of genetic research, the techniques used can also be used to manipulate the basic building blocks of life. They also offer a tool for those eager to eliminate embryos with genetic defects— defects that can lead to a life of pain and suffering.

In the preceding chapters we discussed reproductive technologies, including in vitro fertilization. Since 1990 IVF has included pre-implantation genetic diagnosis (PGD). Before the physician transfers the embryo(s) to a womb, he must decide which one(s) are most likely to implant and produce a successful pregnancy. PGD helps doctors make that decision. Once eggs are fertilized in a petri dish, resultant embryos begin to develop. At an appropriate point, one cell is removed from the embryo and tested for genetic abnormalities. This doesn’t harm the developing embryo, but it does allow the physician to transfer to the womb only healthy embryos without any known genetic defects.2Recently, Dr. Joel Brash, medical director of Chicago IVF fertility clinic, claimed that “doctors can spot genetic markers for cystic fibrosis, breast cancer, ovarian cancer, multiple types of leukemia and hemophilia. Down syndrome also is identifiable through PGD. And by using embryos without any of the markers, the diseases can be removed from a family’s gene pool.”3

Though scientists and physicians debate its benefits, PGD is increasingly performed. Worldwide it is estimated that in 2000 some 2,000–3,000 PGD procedures were done, and by 2007 estimates were between 5,000 and 10,000 a year. Moreover, a study in 2006 by Johns Hopkins University’s Center for Genetics and Public Policy reported that “74 percent of the 186 in-vitro fertilization centers surveyed offered PGD services to their patients. The clinics reported doing approximately 3,000 PGD procedures in 2005, and authors of the study estimated that 4 percent to 6 percent of all in-vitro cycles included PGD.”4

But how can it be possible to identify with certainty genetic markers that control diseases? The answer involves the Human Genome Project. With developing knowledge of genetics it became clear that many diseases are caused by defective genes. If we knew which human traits are linked to each gene, then scientists could tell when a given gene is defective and causes a disease. With this information, a strategy could be devised to correct the defect and thereby prevent or cure the disease.

Humans have twenty-three pairs of chromosomes. For some time it was thought that these chromosomes contained more than one hundred thousand genes.

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