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 Annual 2013

Annual 2013

 

           
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Decoding Genetic Testing

Studying Genes to Predict Future Health

Imagine being able to determine your risk of future disease—and, as a result, reduce the likelihood of developing diabetes and heart disease.

It’s actually possible with genetic exploration. And these days, testing for genetic disorders, which can predict a somewhat reasonable outcome, has become almost as simple as taking a home pregnancy test. Several companies, including Mountain View–based 23andMe, offer consumers a direct-to-consumer testing service to determine whether your genes put you at an increased risk of developing an array of health conditions including macular degeneration, Parkinson’s disease and other maladies. For $299, consumers can register with 23andMe and send in a saliva sample to understand how their genes may impact their future health. Other national companies, such as Inherent Health and deCodeme, offer tests that can be ordered off the Internet and range from several hundred dollars to more than a thousand.

Redwood City’s Counsyl takes a slightly different approach to genetic testing by offering a collection kit to prospective parents that determines their risk for passing on more than 100 different genetic diseases to their child. The test is already covered by some major insurers and has the potential to expand preconception screening to include many rare inherited conditions.

While knowing your individual risk of certain diseases can be empowering and allows you to make lifestyle changes geared at minimizing the chances of developing certain conditions, experts say the tests are useless unless administered with proper medical guidance.

The National Society of Genetic Counselors in Chicago (www.nsgc.org) recommends that patients meet with a genetic counselor before undergoing genetic testing and maintains a list of counselors across the United States to help families accurately read their genetic test results.

“It’s important to consult with a genetic counselor before, during and after undergoing genetic testing,” says Veronica Jackson of the NSGC. “The counselors can help you to understand what to expect, what may be found on the tests and to help interpret the results to avoid confusion and misinformation.”

While the tests may appear straightforward, medical experts caution against using genetic tests as a single tool in predicting your health future. A June 2012 study in the journal Public Health Genomics reported that although consumers think direct-to-consumers genetic test results are easy to understand, they may not interpret them correctly. The researchers also noted that if consumers misunderstand the meaning of their direct-to-consumer genetic test results, they might experience unnecessary anxiety or feel falsely reassured about their health. Both outcomes could ultimately cause harm if, for example, they led to unwarranted changes in screening behavior.

The NSGC recommends that consumers meet with a counselor who is specially trained in genetics to not only help them understand and interpret the test results, but to also provide information on possible interventions. The counselor, the NSGC says, should also be equipped to refer patients to support services.

Esther John, Ph.D., a senior research scientist at the Cancer Prevention Institute of California in Fremont, says gene testing provides only one piece of information about a person’s health. The outcome is not the sole predictor; other genetic and environmental factors, lifestyle choices and family medical history also affect a person’s risk of developing many health conditions.

“These tests show that you may be at an increased risk, but they don’t say definitively that you will get a certain disease,” John says. “Whether you choose to get a genetic test or not, there are a number of lifestyle choices people can make to lower their risk of developing cancer and other diseases.”

Organizations such as the American Heart Association, the American Cancer Society and the American Diabetes Association all agree that maintaining a healthy body weight, quitting smoking, getting regular exercise, limiting alcohol consumption and eating a good diet rich in fruits and vegetables, poultry, fish and low-fat dairy products can help to decrease a person’s risk of heart disease, stroke, diabetes and more.

While John believes that genomic medicine has opened up exciting opportunities for doctors to improve diagnosis, treatment and prevention of certain diseases, she says the field is still evolving.

“There’s no doubt that genetic testing will play a larger role in cancer risk assessment, detection and treatment in the future,” John says. “There are some tests that are now available, and some that are still developing, that allow doctors to use the info obtained from genetic testing to personalize a patient’s medications.”

Before deciding to undergo gene testing, experts urge consumers to talk with their doctor and consult with their insurance plan to determine coverage. Some direct-to-consumer genetic tests and genetic counseling services are covered by insurance, and others can only be ordered with a physician’s referral.


Predicting Your Future Health
Harvard Medical School notes that by middle age, medical exams and screenings have given most people a good idea of their risk for heart disease, diabetes or osteoporosis. If you’re still uncertain, you can consult one of the well-established cost-free risk calculators, which include the Framingham Risk Assessment Tool for heart disease (www.health.harvard.edu/heartrisk), the Diabetes Risk Test (www.diabetes.org) and the FRAX tool, which estimates the 10-year likelihood of a hip or other major fracture (www.shef.ac.uk/FRAX).

Read the new book Am I My Genes? Confronting Fate and Family Secrets in the Age of Genetic Testing by Dr. Robert Klitzman, professor of clinical psychiatry at the College of Physicians and Surgeons at Columbia University in New York, who ponders the ethical issues behind genetic testing.

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