Test of a Lifetime
There Are Still No Clear Answers on Genetic Testing for Diseases
When Karen Milek was in her mid-30s, her mother was diagnosed with Huntington’s disease. While grappling with their mother’s illness—Huntington’s is a devastating, progressive and ultimately fatal neurological disorder—Milek and her three siblings had to make another difficult decision: whether or not to get tested to see if they, too, carried the genetic mutation that causes Huntington’s. Each sibling had a 50 percent chance of inheriting the mutated gene that their mother carried, and if they did carry the gene, they would definitely go on to develop Huntington’s, probably by their late 30s or early 40s.
Milek and her younger sister chose to get tested; her older sister and a brother decided that they didn’t want to know. “I’m the kind of person who’s always been curious and needed to know things. I actually got a degree in medical technology and worked in a lab for a time, and I’ve always believed that things are better off when you know about them than if you don’t,” Milek said.
That conviction was tested when her results came back—both Milek and her sister carry the mutated Huntington’s gene—but she’s still convinced it was the right thing to do. Over the past decade, she’s participated in two Huntington’s clinical trials and has traveled the world for Huntington’s research. “My outlook on this whole thing is positive. I feel like this is why I’m living. I’ve found a place that I can help other people. This is my chance to really live each moment.”
But Milek is the first to admit that not everyone is in the same position she is. “I have security in my job, secure health insurance and secure long-term care insurance,” she said. “At a Huntington’s convention I went to, one of the leading researchers, Dr. Martha Nance, said it was OK not to get tested if you weren’t ready. To know is not as important as being healthy and just enjoying your life. If you ask the people who do get tested, many of them do regret it.”
To test or not to test? That is the question facing many people whose family history places them at increased risk for certain diseases that have a genetic component, such as Huntington’s, breast cancer, Alzheimer’s and other conditions.
If, for example, early-onset Alzheimer’s disease runs in your family, you might choose to be tested for the genetic mutations that have been linked to this particular form of the disease (which only accounts for about 6 percent to 8 percent of Alzheimer’s cases). If your mother and aunts all developed breast cancer at a young age, they—and you—might choose to be tested for the genetic mutations BRCA1 and BRCA2, which are associated with an increased risk of breast and ovarian cancer.
As we learn more about the genetic factors involved with various diseases, more and more predictive genetic tests will become available. As of 2003, according to a presentation by National Human Genome Research Institute Director Francis Collins at the World Economic Forum, more than 900 genetic tests were offered by diagnostic laboratories. But as Milek pointed out, just because you can get a particular genetic test for a certain disease, doesn’t mean that you should. So how can you decide whether genetic testing is right for you?
First, decide what you want to do with the information you’ll get. Is there a treatment available? If not, what else might the knowledge that you do or don’t have a particular genetic mutation give you? “If there isn’t yet a treatment, you’re getting information for the sake of having information,” said Dr. Edward McCabe III, a genetic medicine specialist at UCLA and former chair of the Secretary’s Advisory Committee on Genetic Testing at the Department of Health and Human Services. “Now, that too may be a very important reason for doing the test, in order to help you plan. But if there’s an intervention, then there’s even more reason to do the testing.”
Second, how might the information affect you emotionally? “Testing can be reassuring, but when it isn’t, it can have a very unsettling impact on patients,” said Dr. Susan Pauker, chief of the Genetics Department at Harvard Vanguard Medical Associates and an associate professor at Harvard Medical School. “People are surprised at finding out they’re a carrier of a genetic mutation, and they’re often surprised by the shot to their self-esteem and how insulting it feels.”
Third, how might the information affect you financially? That is, could you lose your job if your employer found out you were likely to develop Huntington’s in the next five years? Could you be dropped from your health insurance or life insurance plan if the insurer found out you carried the BRCA1 mutation?
“There is a real risk of genetic discrimination,” said McCabe. “I’ve seen articles in the genetics literature that claim there is no evidence of this, but cases [have] gone before the Equal Employment Opportunity Commission and other bodies, and clearly this is a real phenomenon.”
Legislation to ban genetic discrimination has been introduced in every session of Congress since 1995, but federal protections have yet to pass. Most states have passed laws limiting genetic discrimination for some kinds of health insurance, and more than 30 states ban or limit genetic discrimination in employment, according to an article in the New England Journal of Medicine in September 2005.
Still, this patchwork of state laws does not provide complete protection, said Pauker. “Here in Massachusetts, we passed a very good law in 2002 protecting against genetic discrimination in health insurance and employment—but life insurance, disability and long-term care insurance are all exempted,” she explained. “I just saw a man whose two children have a genetic disorder, and we discussed whether or not he wants to take the risk of being tested for it himself. It would change his management of his own health, but it would also potentially threaten his ability to have life insurance to care for the kids in the event of his death.”
Finally, if you do consider all these factors and elect to get tested, what kind of follow-up support will you have? “There’s no point in doing the test if you’re not going to have good follow-up,” said McCabe. “And in many states, with the number of tests being done, the follow-up system is already stretched because of course the money isn’t in follow-up, it’s in the testing itself.”
It is also very important to understand that unless you yourself have the particular disease, you are probably not the one who needs to be initially tested. “Let’s say you’re part of a family with familial breast cancer. One of the things I see very commonly is that there is such a history, a woman is concerned about her risk, and she goes to get tested. The test comes back negative for the BRCA1 and BRCA2 mutations, and she’s very relieved. But that really hasn’t told us anything,” McCabe said. “There are some other mutations associated with familial breast cancer, and it could be one of those. Unless you have a proband—a person who has the disease—willing to be tested, a negative test in everyone else doesn’t mean anything. We don’t know if it’s a true negative, or if this is a family where we haven’t identified the mutated gene yet.”
If all of this sounds confusing, that’s because it is. If you are considering predictive genetic testing, the specialists who can guide you through this difficult decision-making process are called genetic counselors and medical geneticists. You can find a medical geneticist near you by searching the online directory of the American College of Medical Genetics online at http://genetics.faseb.org/cgi-bin/srchacmgn, and a genetic counselor by clicking on “find a counselor” at the Web site of the National Society of Genetic Counselors (www.nsgc.org).
Ultimately, however, the decision about testing is yours and yours alone. “It’s critical that a patient’s values be the main driver of education about testing,” Pauker said. “Doctors and counselors can provide facts and individualize them for a person’s situation, but that person has to carefully consider their own values before they choose testing or screening.”
Gina Shaw is the medical writer for The Washington Diplomat.
