Genetics, Genomics, Genethics: Course Preview


This discussion was selected from Week 6 of the AMNH online course Genetics, Genomics, Genethics, part of Seminars on Science, a program of online graduate-level professional development courses for K-12 educators. This is an excerpt from an actual course discussion, but learner names have been changed. Explore more sample resources...

Hypothetically...if you learned there was the option, right now, to be tested for a number of diseases to determine whether you have the gene versions that predispose you for any of these diseases, would you choose to be tested? What are the factors you would consider when deciding whether or not to be tested?

Kara 26 Sep 6:32 PM

My first thought after reading this question was about my age. Because of my natural scientific curiosity, if I were many years younger, I would consider having the test. But, I did say consider. Because I am doing my final project on genetic privacy and discrimination, I have done a lot of reading on genetic testing. Before doing this reading I would have "jumped in with both feet" so to speak. Now, I would be more cautious.

According to an article from the National Human Genome Research Institute, we all have "a half a dozen or more genetic mutations that place us at risk for some disease. That does not mean that we will develop the disease, only that we are more likely to get it than people who do not have the same genetic mutation that we do" (1) This statement contains two important pieces of information. First, if I had the genetic test, chances are that the results would show several genetic mutations. I would have to be prepared mentally to hear something that may be unpleasant. What would I do if I found out that I had the genetic predisposition for a non-treatable, fatal disease? Just because I have the genetic mutation does not necessarily mean that I would get the disease. As we have discussed in earlier weeks, gene expression and the environment can influence whether someone will contract a genetic disease. So, would I live in fear of getting this fatal disease? And what if the disease that I might get is not fatal? If I needed to change my way of life, my habits, my environment or that of my family would I do it? Unfortunately I am asking more questions than I am answering.

An additional concern revolves around what other people would do with the information. Despite state laws, cases of insurance discrimination are occurring in this country every day. People who are currently having genetic testing because a genetic disease "runs in the family" are, in many cases, paying for the genetic test out of their own pocket. This is to avoid discrimination by employers or insurance companies. Although there are federal laws pending that prohibit genetic discrimination, I would want to know the policies of my current health care provider, the laws of the state and who would have access to my genetic information.

Although I have no children, I would also consider the impact on my family. If I found out that I had a genetic predisposition to a disease, would I tell my sibling? Would he want to know? The advantage of knowing about the possibility of genetic disease, beyond changing your lifestyle to prevent it, would be to plan for long-term care so as to not be a burden to the family. However, if the insurance company found out that I had the genetic predisposition for a disease, it might be impossible or too expensive to get long-term care insurance.

If there were a reliable test to predict Alzheimer's disease, I would pay for it myself and have it tomorrow. Until then, I will just have to keep taking courses like this to keep the wheels turning in hopes that an "ounce or prevention is worth a pound of cure".

Evan 29 Sep 11:59 AM

"I would want to know the policies of my current health care provider, the laws of the state and who would have access to my genetic information." Boy, after reading this - I think it is too much work to know my genetic disposition!

Instructor Gary 29 Sep 1:35 PM

Accuracy and interpretation?........That does not mean that we will develop the disease, only that we are more likely to get it than people who do not have the same genetic mutation that we do. The issue of interpretation is very important in this discussion, Kara. Sarah is looking at the same issue. What does that positive result really mean? Your decision about testing also seems to involve the accuracy of the test. What are the chances of false positives and false negatives? Can they be 100% accurate? Would you be satisfied with 90%? How about 50%? Gary

Diane 29 Sep 6:44 PM

Hi there
I agree with what they have to say about a percentage. This would definitely be something to weigh in on when deciding to get the test or not. I guess it is important to remember that any genetic test is only passed on probability. My question is, without getting the test don't we all have the same probability? I mean there is a chance that one of us will have cancer at one point in our lives.

"Prostate cancer in 15 percent to 30 percent of men over the age of 50 and in 60 percent to 70 percent of men who reach age 80", this is a reality for men.

Or if you are a female: "it is estimated that a female child born today has a 12.3 percent chance of developing breast cancer during her life"

These percentages are based the numbers who have cancer regardless if they have the genetic mutation or not. So regardless if you get tested or not aren't we still playing the "probability" game? Just a thought... Diane

Justine 5 Oct 3:56 PM

Wow, interesting thought, Diane!
So if we all have a probability to have some sort of disease, why not life your best life? Geez, that sounds a little too like Oprah... In a terribly morbid, oversimplified way we ARE all playing the probability game...and the only certain outcome is death. And taxes :)

Scientist Juliana 29 Sep 9:50 PM

Diane and Justine, you brought up another good point. Ultimately we would all fail genetic testing! We all have a certain probability to become sick.

I wanted to add a little more information on probabilities and complex diseases. So far we only understand very few genetic diseases and most of them are only due to one gene. For some of the gene mutations it is clear that the carrier has a 100 percent probability to become sick, like Huntington and cystic fibrosis and a certain rare form of colon cancer, for example. I could imagine that a high frequency of a disease within a family would make a genetic test (if available) more reasonable than just having all sorts of different tests. Juliana

Syed 30 Sep 6:08 AM

Some genetics tests will tell you that you definitely get the disease. But even with Huntington's disease, I understand that there is variation in the severity and time of onset of the disease so even though the genetic marker indicates that you will get the disease, when and how fast it will progress seems to be variable. I would be satisfied 90% accuracy but less than that would leave me with too many questions. At this point, even if there was a test for Alzheimer's, I would hesitate to have it unless they had a treatment for the disease. More than the accuracy, the availability of treatment would matter in my decision to have the test.