Genetic testing a mixed blessing

VIEW ON HEALTH

His father died at an early age from undiagnosed heart disease problems. His mother’s father also had serious issue with his heart. So when Bert Fortne read in the news last month that he could get affordable, over-the-counter genetic testing done at home, he was intrigued, and ready to buy.

“I didn’t do a lot of research or anything, like you’re supposed to,” the retired salesman said. “But I thought it was pretty straightforward, a test for your genes, the ones that you should be afraid of.”

That’s exactly what some physicians fear.

While genetic testing is a positive medical tool, receiving that genetic information from a test while at home, without a professional in the medical or genetics field, can lead to a misunderstanding or misinterpretation of the results.

The ability to test at home was delayed in early May when Walgreens pharmacies decided not to sell the genetic kits from Pathway Genomics, a San Diego, California-based company. The U.S. Food and Drug Administration was skeptical about the tests and did not approve the product without further testing and research. Genetic experts also were wary of the tests at this point in consumer education about the field in general.

“We’re not planning to move forward with offering the Pathway product to our customers until we have further clarity on this matter,” Jim Cohn, a Walgreens spokesman, said. “It’s been postponed, for now.”

But not completely taken off the table for those interested, and it appears to be quite a few are. If anything, the tests have opened a discussion between physician and patient about the importance, and understanding, of their genetic makeup and its link to their overall health.

Pathway Genomics created a kit that is simple to use and costs about $20. The kits contain a plastic tube that consumers use to hold their saliva and a postage-paid envelope to send the sample to a laboratory. The lab analyzes saliva samples to evaluate that specific person’s risk of more than 70 diseases including heart disease, hypertension, diabetes and lung cancer based on their genes. The lab testing can cost anywhere from $79 to $249. Some insurance plans cover genetic counseling, particularly when your doctor gives a referral to a qualified genetic counselor.

One of the more controversial aspects of the tests is its purported ability to check for carrier testing for pre-pregnancy planning. This includes testing for mutations that can cause serious or life-threatening genetic disorders such as cystic fibrosis and Tay-Sachs disease.

Geneticists aren’t sold on the idea. They worry that the scientific understanding is not accurate to the point that it can assess risks for such common diseases as cancer and heart disease. It’s a matter of what the information means, said Dr. Robb Rowley, a board-certified internal medicine physician with Amigenics, and is currently adjunct associate professor at Touro University in Las Vegas.

“We don’t want patients to not get testing, but they should get quality information, not get information that is detrimental to their health,” Rowley said.

Amigenics is a group of physicians and genetic counselors based in Las Vegas that provides genetic evaluations, counseling and testing for genetically influenced conditions in adults.

Rowley sees up to nearly a dozen patients a week. He is consulted on numerous types of cancers, such as breast, ovarian, colon, and thyroid. Amigenics has also evaluated conditions involving the central nervous system or metabolic disorders like hemochromatosis and numerous other system – or condition-based complaints or disorders, according to its website.

More and more patients are considering genetic counseling as part of their normal routine, said Erica Ramos, MS, CGC, senior genetic counselor at Amigenics.

“For certain patients it’s part of their standard medical care,” she said, and becoming more popular as physicians and consumers understand more about how genetics play a role in treatment for some diseases.

Direct-to-consumer testing has been discussed for years.

“Genetic tests of individuals or families for the presence of or susceptibility to disease are medical tests,” the American College of Medicine Genetics Board of Directors said in a statement as early as 2004. “At the present time, genetic testing should be provided to the public only through the services of an appropriately qualified health care professional. The health care professional should be responsible for both ordering and interpreting the genetic tests, as well as for pretest and posttest counseling of individuals and families regarding the medical significance of test results and the need, if any, for follow-up. Due to the complexities of genetic testing and counseling, the self-ordering of genetic tests by patients over the telephone or the Internet, and their use of genetic ‘home testing’ kits, is potentially harmful. Potential harms include inappropriate test utilization, misinterpretation of test results, lack of necessary follow-up, and other adverse consequences.”

Genetic counselors have Master’s degrees in their field as well as training in medical genetics and counseling in their field so as to better assist the patient with this detailed, sometimes disorienting information.

“Distributing genetic testing through pharmacies will expose more people to its availability,” Elizabeth Kearney, president of the National Society of Genetic Counselors, said on May 11 in direct response to the FDA’s decision to not approve the at-home genetic tests. “However, people should first meet with a genetic counselor to determine whether genetic testing is right for them and to prepare for what they might learn.”

What might you learn?

For starters, there are pieces of the tests that can be helpful.

“The tests look at 100 changes in your DNA,” Rowley said. “Some of them are very appropriate. They reported the affecting the risks like diabetes but the reality is that it’s really only one page of the story. It’s one small piece of information about the diseases.”

But there are some limitations that geneticists are aware of and the public should be as well.

For instance, many people with a family history of breast cancer might pick up a test, out of curiosity. However, having the marker doesn’t necessarily mean they will get breast cancer.

There are two genes indicative of breast cancer susceptibility, known as BRCA1 and BRCA2. Genetic testing combined with genetic counseling can help determine if a person has an inherited susceptibility to breast cancer and provide an estimate of breast cancer risk for an individual.

“There are some markers for breast cancer and there are pieces that need to be looked at also,” Rowley explained. “BRCA1 and BRCA2 that (are important for understanding the results), and those genes are not tested for in those tests.”

The danger lies in the fuzzy picture the tests can give to a person looking for information on their overall or specific health concerns.

“That can dramatically influence their care, overall,” Rowley said. “In these tests they don’t look at those.”

On the flip side, a marker for breast cancer may not appear on the test.

“A genetic test can say everything looks great, but you might not realize that there are other tests that can show breast cancer (risk),” he said.

Aside from genes, you need to look at other factors, such as lifestyle and environment.

“The genes they are testing for are not the only genes they are testing for and there are other environmental factors you should be looking for,” Rowley said. “It’s not giving you the full picture.”

Think of the information the tests give as one page of a total essay. Then consider that each word of that one page needs to be dissected and understood to give a complete understanding of how the words work together. It’s a rather daunting, complicated process, genetic testing.

“We would want to tell how breast cancer (as an example) fits in a puzzle, and we are only testing for one piece of that puzzle,” Rowley said. “If one of those words isn’t being tested, then you…are not understanding how those words fit together.”

The other piece of the genetic puzzle is that a test can show a low genetic risk for something such as diabetes, but the test user may be at high risk due to lifestyle choices such as diet and lack of exercise.

“Genetics can say what a person can have in their lifetime but not right now,” he said.

If the tests do come to a pharmacy near you, and you decide to roll those dice, make sure to put a few things in place before jumping to any conclusions, good or bad.

“People should tie a physician and genetic counselor in to see that they get good information,” Rowley said. “Not that the tests can’t have value, but it can get complicated. We want to make sure that it is being done appropriately.”

Rowley is serious about the public’s education. He has been and is currently involved with establishing and managing multiple FDA clinical trials, along with presenting original research at international scientific and medical meetings. Some of his most recent publications include articles in Genome Research, Genes and Immunity and the Journal of Immunological Methods.

The NSGC recommends asking many questions before considering taking a genetic test, either at home or under the direction of a physician or qualified genetic counselor.

Ask what the test will tell you, what the scientific basis is for the testing, what you will do with the information once you know what it is, good or bad and will a physician who is qualified be involved in the testing.

“We are learning more and more about genes and how family health impacts us as adults,” Ramos said. “If you are concerned about your health, asking for a referral to a genetic counselor can help you better understand any risks (that may come from your genes).”