If your teenager was genetically predisposed to a disease, would you want him to get a genetic test? Would you want him to know the results even if he has a risk of getting the disease only later, as an adult? And even if your teen might have a right to know, what if he doesn’t want you to know, to keep you from worry and fear? Does he have that right?
Research shows that most teens say they would want to know the results of genetic testing. Doctors agree that, more and more, genetic testing will play a role in detecting and treating disease. The more we look toward genetic testing, the more we will grapple with big medical and ethical questions.
If you have a family history of disease and you or your teen is interested in a genetic test, consider these issues first.
What are the types of testing?
Genetic testing is a rapidly changing field. Two types of predictive genetic testing will let you know if you have a particular disease or risk, says Kimberly Quaid, Ph.D., director of the predictive testing program at Indiana University.
First, presymptomatic testing can help determine whether or not a person will develop a particular disease, such as Alzheimer’s disease or Huntington’s disease, before any signs or symptoms occur, Quaid says. This is especially helpful if you have a family history of a disease like Alzheimer’s or Huntington’s. This type of test can predict with 100 percent certainty whether or not you will get the disease, says Quaid.
The second kind of test, susceptibility testing, can identify those mutations that increase a person’s risk for a disease such as cancer. Patients may know if they have an increased risk, says Quaid, but the test results are not a definite confirmation of whether or not they will get the disease.
Why would a teen get tested?
According to Dr. Sophia Hufnagel, a medical geneticist with Children’s National Health System in Washington, D.C., medical literature over the past 30 years has put forward pros and cons associated with adolescents and genetic testing. “The classic reason against testing is that it can increase anxiety,” says Hufnagel, who conducted a survey with teens and genetic testing. Another reason, says Hufnagel, is that it could lead to dissension within a person’s family because “genetic testing is not about one patient; it’s about the entire family.” Genetic testing can also impact future choices or lead to discrimination by peers or even insurance companies, says Hufnagel. Finally, testing can lead to unclear results.
But in recent years, attitudes have shifted toward teens’ rights to know their own medical information. Newer studies have shown that teens might experience a feeling of relief from knowing more about their genetics, Hufnagel said. Other reasons to test, Hufnagel says, are that positive test results may lead to the diagnosis for other family members and aid in family planning, and could even lead to a person to decide to enter a clinical trial or research project.
Testing a teen brings up a host of even more complicated issues: Whose right is it to decide? Who gets the information? Do you fully inform your teen of what you learn?
What should you know before you are tested?
While these tests will tell you whether you have a probability or perhaps a certainty of developing a particular disease, often the question is whether you want to know the results. Before going ahead with testing, it’s important to determine first whether you really want to have the information it will provide, and whether you want it now.
Testing a teen brings up a host of even more complicated issues: Whose right is it to decide? Who gets the information? Do you fully inform your teen of what you learn?
A recent position statement from the American Society of Human Genetics (ASHG) urges parents to consider whether there are any “clinical intervention benefits appropriate in childhood” before testing. Absent those benefits, the society recommended that parents be encouraged to defer susceptibility or presymptomatic testing for adult-onset conditions until teens reach adulthood.
Testing can be especially problematic from a privacy standpoint, says Dr. Lainie Friedman Ross, a professor of clinical ethics at the University of Chicago.
“First, some adults choose not to know this information, so by testing the child, you remove the child’s [future] right to not know as an adult,” Ross says. “Second, even if the child would still desire, as an adult, to have the information, the child has a right to privacy about health problems that will not develop until adulthood.” By testing your child, Ross says, you take away her right to privacy regarding her own health information.
Finally, it is important to remember that most genetic information is probabilistic, Ross says. “Getting the information now doesn’t ensure the same interpretation 10–20 years from now, so it must be explained that repeat testing down the road may be necessary.”
What is informed consent?
If your teen is interested in genetic testing, first encourage him to discuss these issues thoroughly with you and his physician. Generally, informed consent means that a person should fully understand the testing procedure, its benefits and limitations, and possible consequences of the test.
Quaid likes to start with a family history, and then explore exactly what types of risks are or might be present. After this, she discusses with the patient how much the patient knows about the disease and its impact. Finally, she’ll ask why the patient wants to be tested and what major decisions need to be made. Informed consent, in the case of testing a minor, is especially critical if the testing is done for adult-onset diseases, because of the impact on a teen’s right to privacy. As a result, teens and their parents should consider obtaining counseling before testing, Ross says.
What comes next?
Once counseling has been completed, a medical geneticist, primary care doctor or nurse practitioner may order the test. The test is performed on a blood, hair or skin sample and then sent to a laboratory for examination. The examination looks for chromosomal, DNA or protein changes, depending on what disorder is suspected. The laboratory then issues a report to the physician.
Whether or not to then share the test results is a big question for any parent. Some test results may help teens and their parents to plan better for their future health. At other times, because the results may not be 100 percent certain, parents must be cautious and not assume their child is destined to get a particular disease such as cancer.
A recent survey conducted by the Cincinnati Children’s Hospital Medical Center found that 83 percent of teens would prefer to know the results, even if the results indicate adult-onset disease, which the teens couldn’t do anything about at that point in their lives. Of those who preferred to know the results, they cited future planning as a key reason. Teens wanted to be able to plan their education, career choices, relationships and reproductive choices in light of their results.
This is not surprising, says Quaid, because the age limits for testing keep moving back. Previously, Quaid says, she was seeing primarily 30- to 40-year-olds but she now sees many 19- to 21-year-olds. “They are the first generation who have grown up with genetic testing and being able to know that they can make decisions about their careers and lives with the possibility of an adult-onset disease.”
Are at-home tests reliable?
There are at-home genetic tests directly marketed to consumers.
Generally, a test kit is mailed to a person’s home. The sample is collected by the person at home and then returned via mail to the genetic testing company. According to ASHG, these types of tests are risky because of the lack of pre-test or post-test counseling and clinical interpretation of the test results, as well as inadequate validation of some tests. One big concern is testing children for adult-onset diseases without these safeguards.
Another problem with these tests, says Quaid, is that they don’t do an adequate job of educating people about the testing process. This is because the tests are distributed directly by businesses and testing companies, not by health care providers who have knowledge of the outcomes and risks.
Ross generally discourages adults and teens from getting at-home testing. But if individuals are considering it, she says, they should understand that the medical community’s understanding of genetics and the genome is constantly evolving. “Information we give to the patient today,” Ross says, “may be inaccurate next month.” But most importantly, she says, despite the test, we must remember that “genetics cannot predict your future health with a certainty — at best, it can only give you probabilities.”
