Genetic Testing: Do You Really Want to Know ?

Shalisa Salla, PharmD Candidate 2011

Bernard J. Dunn School of Pharmacy, Shenandoah University

Prepared during Consumer Health Information Corporation Clerkship
McLean, VA

In May 2010, news broke that Walgreens pharmacies would begin selling an over-the-counter genetic test that could predict a person’s risk for getting a disease or how they might respond to a drug. All a person would need to do is send a sample of their saliva to the test maker. The test makers would then assess their genes and send the results back.

FDA has put that plan on hold. It claims that the test maker, Pathway Genomics, did not have the agency’s approval before it advertised its product. FDA warned consumers that, “claims made by a company with a test that is not approved have limitations and should not make important medical and lifestyle decisions without first consulting a health care professional.”

Walgreens has decided not to sell this genetic test until the matter between Pathway Genomics and FDA is resolved.

Would you want your genes tested?
Even though genetic testing is not sold in drugstores yet, it has paved the way for personalized medicine. Scientists are now able to identify 20,000-25,000 genes. This can help to predict who may be at higher risk for having a certain disease or drug side effect. There are two main types of genetic testing:

Disease Risk
Imagine you are a 27-year-old woman whose mother was diagnosed with breast cancer five years ago. Now your 30-year-old sister is diagnosed with breast cancer. Would you want to be tested to see if you were at risk for breast cancer?

Women that may have breast cancer genes that are not normal have a 60% to 80% chance of developing breast cancer. Genetic testing might be right for them.

Genetic testing and counseling can give people the chance to learn about their risk of getting a disease. Doctors can offer suggestions to help manage that disease. People would then be able to choose a course of action that is best for them, such as a breast exam. Genetic testing is of value because it may allow people to detect and prevent certain diseases from occurring.

Medication Response
Now imagine you were diagnosed with depression and given a medicine by your doctor for treatment. Two weeks later, you feel sick to your stomach and think the medicine is not working.

A person’s response to a medicine is hard to predict because everyone has different sets of genes. Your particular genes can affect how your body processes certain medicines. Some peoples’ bodies break down or use medicines slower than others. This can lead to unexpected side effects if they build up and stay in the body too long.

The opposite is true when medicine is used up too fast. These people may find no benefit in taking their medicine because the drug is not at high enough levels in the body to work.

Having a genetic test done before taking a medicine can help to predict if someone is more likely to have side effects. A doctor would be able to adjust the dose of the medicine or prescribe a different drug that will work for them.

Concerns
There needs to be more research on genetic testing and the need for people to have counseling available. Sekar Kathiresan, a researcher whose work led to the finding of gene alterations linked to early heart attacks, said, “Often we don’t exactly know what we would do differently based on the genetic test result.”

Another concern is that patients may have a range of emotions, including anxiety and depression when they find out they are at risk for a disease.

Although genetic testing may soon be offered to many people, a person needs to weigh the benefits and the risks of genetic testing before making a decision.

Which path would you take?
Although genetic testing is in its early stages, it is the wave of the future. The question everyone has to ask themselves is, “Would I want to have a genetic test?” For some, testing may mean early diagnosis once the risk of a disease is known. For others, it may mean avoiding side effects from a drug and having a doctor choose a medicine that works.

People also need to think about if they could live a normal life once knowing their test result. Some people may make lifestyle changes to prevent the disease. Others might become afraid and constantly worry about getting the disease.

Genetic testing is a tough decision to make. People should speak to their family, doctor or genetic counselor before choosing which path to take.

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