Sometimes it is All in the Genes

Part I—"The Genetic Test"

by
Anne Galbraith and David Howard^*
Department of Biology
University of Wisconsin—La Crosse

"Your pregnancy seems to be progressing just fine, but we'll do some blood work to be on the safe side. As long as we're drawing blood from you today, Nancy, would you consent to participate in one of the genetics studies we're conducting here at People's Best Hospital?" Dr. Kwin prided herself on putting her patients at ease, but her question caught Nancy a little off guard.

"What would that entail, Dr. Kwin?" While Nancy believed Dr. Kwin wouldn't ask her to do anything that wasn't a good idea, she never said yes to anything until she had all the information.

Dr. Kwin began to explain, "Well, as you know, PBH is a research and teaching hospital. One research team is trying to determine the frequency of the gene for the genetic disorder cystic fibrosis in the U.S. population. And since you are having blood drawn anyway as you enter your second trimester...."

Genetic disorder? Cystic fibrosis? The phrases made Nancy feel panicky. She interrupted Dr. Kwin mid-sentence. "You don't think I have that disease, do you? Isn't cystic fibrosis serious? How could I have caught it?" The questions came out in a rush.

Hearing the anxiety in Nancy's voice, Dr. Kwin quickly reassured her. "No, no. I'm quite sure that you do not have cystic fibrosis. You can't 'catch' it; you can only inherit it. If you did have cystic fibrosis, you would have been diagnosed when you were a toddler. You have absolutely nothing to worry about. However, let me emphasize that if you feel uncomfortable about participating in this study in any way, just say 'No.' My feelings won't be hurt. There is no pressure to participate."

"If it's inherited and I don't have it, why would they want to test me?" The situation still didn't make sense to Nancy.

"First, let me explain some basics. Cystic fibrosis, or CF, is a disease that is caused by defects in a particular gene. Actually because CF is genetic, 'disorder' is a better term than 'disease.' The word disease should really be used for illnesses caused by bacterial or viral infection. However, people use both words for CF.

"The reason that they need to include people who don't have CF in the study is that cystic fibrosis is a recessive disorder. With a recessive disorder, a person has to have two defective versions of the CF gene to have CF. Therefore you can be a carrier of one defective version but not have CF at all. It is precisely that which has inspired the study. They want to know what percentage of people in the United States carries one defective gene for cystic fibrosis. That percentage is called the gene frequency and can provide a lot of information for people working on CF."

Dr. Kwin went on to explain, "CF is one of the most common genetic disorders among Americans of European descent. Although it has many symptoms, the worst are severe respiratory problems that typically lead to death around the age of 30. One of the first reliable tests for any genetic disorder was the one developed for CF in 1990. Because CF is one of the first inherited illnesses that researchers have been able to get a handle on, these sorts of genetic screenings are pioneering work not only for CF research but also for understanding other genetic ailments."

Nancy considered the flood of information for a few seconds. "I can't see what harm it would do. You run so many tests on me anyway. What's one more?"

"I'll have one of the staff bring you the consent forms and explain the procedure to you further. If you do consent, your biggest decision will be whether or not you want to have the results reported to you. You need to think carefully about that question before signing the consent form."

As Dr. Kwin left the room, Nancy thought to herself, what are the pros and cons of knowing the results?

Questions:

Discuss why Nancy might or might not want to know the results of her blood test for CF.
Dr. Kwin told Nancy that she has "absolutely nothing to worry about." Although Nancy cannot get CF, is Dr. Kwin's statement entirely correct?
Did Dr. Kwin provide Nancy with enough information about cystic fibrosis and the test to make a good decision?
Should Nancy consent to the test? Provide the reasoning for your answer.

Go to Part II—"Sharing the Bad News"

^*Note: Both authors contributed equally to this case and its teaching notes.

Date Posted: 09/24/02 nas
This file is also available in Adobe Portable Document Format (PDF).