If you could find out if you have a gene that increases your risk for breast cancer or depression by ordering a home test kit on the Internet, would you do it?
A growing number of companies are now advertising genetic testing directly to the public over the Internet. For a few hundred dollars or less, you can order a testing kit online, submit a sample of saliva or blood, and receive information about your individual genome within a few weeks. The companies assert that the tests assess your genetic risk for a wide range of health conditions, including heart disease, stroke, various types of cancer, Type-2 diabetes, allergies, migraine, osteoporosis, Alzheimer’s disease, Parkinson’s disease, rheumatoid arthritis, and multiple sclerosis. Some companies offer advice about diet and nutritional supplements based on your results.
For most of the 20th century, genetic disorders were diagnosed primarily by noting the presence of the disorder in a family tree across multiple generations. In the past 20 years, however, advances in genetic research have allowed scientists to identify the genes responsible for many inherited single-gene diseases, such as sickle cell disease, Tay-Sachs disease, Huntington’s disease, and cystic fibrosis. At first, genetic testing was done to determine whether someone who showed symptoms of a genetic disease was a carrier of a genetic disorder, to predict the adult onset of a genetic disorder, or to screen newborns for genetic defects. Testing was done in a clinical laboratory by order of a physician, and genetic counseling was available to help the patient understand the results.
Now, with the rapid expansion of expertise and technology, genetic testing has moved into the commercial realm of for-profit business. Direct-to-consumer marketing bypasses physicians, clinics, and insurance companies to appeal directly to healthy people who may or may not have a family history of a genetic disorder. The vast majority of the diseases they test for are multifactorial—that is, several or many genes interact with each other and the environment to affect risk.
The advantages of personal genetic testing appear evident at first glance—convenience, time savings, cost savings, privacy. You may also feel a sense of empowerment by gathering your own health information, and you may be motivated by this information to make healthy lifestyle choices or follow screening recommendations if you know you have a genetic risk for a condition.
There are also disadvantages. Often, the claims made about how much information the testing can provide are not adequately backed by evidence and thus may be misleading. There is currently no federal regulation of direct-to-consumer genetic testing, although the U.S. Food and Drug Administration (FDA) has informed several home testing companies that they need to submit tests to the FDA for approval. Home testing may also have less quality control over the collection, transport, and testing of your DNA sample than in a medical setting.
Perhaps most importantly, interpreting the results of genetic testing is complicated, and most consumers report they want guidance by a professional. Except in rare circumstances, genetic profiling can only suggest a risk of disease but does not diagnose disease or predict disease with certainty. Because most diseases with a genetic component are multi-factorial, information about genetic risk factors may not be any more meaningful than information about other risk factors, such as poor diet or smoking. Research into the role of genetic testing is expanding, and in 2015, President Obama called for a new research initiative into precision medicine—the use of more personal test information to guide treatments.
If you are thinking about ordering your genetic profile, consider how the results could affect you and how you would use them. If you already know from your family health tree that you are at risk for heart disease, cancer, or other multi-factorial diseases, would genetic testing provide any additional information or be more likely to cause you to pursue the lifestyle behaviors that would reduce your risk?
Answer the following Questions:
• Q:Under what circumstances do you think you would consider ordering a genetic testing kit? What would you hope to find out?
• Q:Genetic testing is available for diseases that as yet have no cures, such as some degenerative neurological disorders. If your family history suggested you might have a gene for such a disease, would you want to know? Why or why not?
Sample Solution