Beyond the Genome: The Ethics of DNA Testing

Article excerpt

Imagine you're playing a board game called GENES-R-US. You roll the dice and pick a card. It says:

You're a 29-year-old pregnant woman. You've just been told you have a gene that almost always causes breast cancer in early adulthood. Your daughter-to-be has inherited this gene. Do you:

(a) abort the fetus to avoid a disease that won't strike for decades?

(b) carry the pregnancy to term and hope your daughter will not develop cancer until a cure has been found?

If you think such a scenario is science fiction, think again.

In September, the news broke that researchers had isolated the long-sought gene responsible for one inherited form of breast cancer. The flawed version of this gene, dubbed BRCA1, is thought to put women at extraordinarily high risk of developing breast cancer (SN: 9/24/94, p.197). Within 2 years, scientists expect to market a blood test to identify those who have inherited the mutant gene.

As geneticists bag their quarry with increasing speed, unresolved medical and ethical issues continue to surface. Society has yet to settle, or in some cases even address, the complex questions that abound in this brave new world. And the road ahead surely contains many more conundrums created by newfound knowledge.

The virtual explosion in genetics research during the last 10 years has led to the identification of genes that underlie heart disease, colon cancer, cystic fibrosis, Duchenne muscular dystrophy, Huntington's disease, and a variety of other ailments that have plagued human beings for millennia.

Researchers around the world continue their feverish hunt for other elusive disease-causing genes, including another gene for familial breast cancer known as BRCA2.

An international team of investigators is closing in on a gene responsible for one type of deafness. Another team has identified the DNA region thought to house a gene for dyslexia, a condition that causes reading difficulties (SN: 10/22/94, p.271).

This fall, researchers reported finding the location of two genes that may contribute to type I diabetes, the most severe form of this sugar-processing disorder (SN: 9/10/94, p.164).

And in an explosive break with tradition, geneticists are beginning to link genes to complex human behaviors, including sexual orientation. Just last year, National Institutes of Health researchers zoomed in on a region of chromosome X believed to contain a gene that may play a role in some homosexual behavior (SN: 7/17/93, p.37).

Such advances bring many tangible benefits to society and to people who suffer from genetic disorders. For example, the discovery of the malfunctioning cystic fibrosis (CF) gene led to the identification of a protein that produces the abnormally thick mucus that clogs the lungs of people with this disorder. Researchers have used that information to fashion new therapies for this disorder. Recently, researchers took a historic first step by inserting a healthy version of the CF gene into the lung of a patient with cystic fibrosis (SN: 9/3/94, p.149).

These examples represent a new frontier in genetic discoveries. The Human Genome Project, a 20-year, multi-billion-dollar effort, aims to chart the estimated 100,000 genes that orchestrate human life. This ambitious undertaking, if successful, means that people of the future may obtain a computerized printout of their genetic code. Couples in such a world may ask for -- and get -- a detailed DNA profile of an embryo floating in a petri dish.

Such knowledge can prove potent. Insurance companies may refuse to offer coverage to a healthy infant whose DNA foretells a heart attack 40 years later. Indeed, some of the thorny aspects of genetic testing have already surfaced. Geneticists offer a blood test for Huntington's disease, yet this illness has no cure. Thus, people who opt for the test may spend years waiting for the first signs of their deterioration. …