Advances in genomic technology have made DNA tests faster and less expensive. That puts genetic testing within reach for many patients. But, if you’re healthy, should you consider DNA testing as part of your routine care? Could understanding your genetics improve screening, diagnosis, treatment or maybe even prevent you from developing a disease such as cancer? On the other hand, could your DNA test results make it difficult to get disability or life insurance?

These are questions that Noralane Lindor, M.D.; Stephen Thibodeau, Ph.D.; and Wyle Burke, M.D., Ph.D., explore in their paper in the January 2017 issue of Mayo Clinic Proceedings. The paper, Whole Genome Sequencing in Healthy People, examines the scientific and ethical issues surrounding the use of genetic testing for predicting disease in healthy people. The authors focus on the use of whole genome sequencing to identify genetic variations that could be tied to disease.  Many scientists point to the whole genome sequencing test as the “ultimate genetic test” because it looks at the entire genome – essentially providing what they call “a genetic selfie.”

Pros and cons

Dr. Noralane Lindor

The researchers explain that while whole genome sequencing has opened a new window into understanding health and disease, most of your genetic makeup still remains a mystery. The authors highlight both advantages and disadvantages for you to consider when deciding whether to have whole genome sequencing as part of your health care.

Advantages

• Approximately two percent of patients tested may learn of a genetic variation that could lead to prevention or earlier treatment of a disease.
• Some patients have discovered a genetic variant that could be present in other family members, leading to a new diagnosis that could save lives.
• Others learn they are genetic carriers of conditions like Cystic Fibrosis, which could impact their decisions about having children.
• Knowledge about disease risk could prompt individuals to make healthy lifestyle changes, such as stopping smoking or losing weight.
• Broader testing of the general population could contribute to the big data that will provide more precise information on the impact of genetics on health and disease for future generations.

Disadvantages

Dr. Stephen Thibodeau

Genetic testing alone cannot predict a person’s potential for disease. The authors state that based on current scientific evidence, lifestyle choices and environmental factors play a bigger role in disease than do most genetic variants.

For example, there are genetic associations for the risk of developing lung cancer or heart disease, but these effects are outweighed by risk factors such as smoking and aging.

Other disadvantages of genetic testing include:

• Little evidence of the overall benefit for healthy patients.
• The vast majority – about 98 percent – of those tested will not have a genetic variant that can definitively predict disease risk.
• Many genetic variations that are not necessarily significant will be identified, which could prompt patients to seek unneeded medical care.
• Family planning based on the test results becomes more complicated as couples weigh risks of passing on a disease.
• No consensus among the medical community about which genetic variations require medical intervention.
• Storing your genetic testing data is expensive, and there are unresolved questions about the best way to protect your privacy and keep your data secure.
• Lack of public policy guiding the use of genetic testing, including concerns about the impact that genetic test results could have on your ability to obtain disability or life insurance.

For now – proceed with caution

The authors suggest that as discoveries continue, the role for whole genome sequencing will become clearer. However, until that time, evidence must be gathered to further define the best way to use this powerful tool.

Mayo Clinic Proceedings Symposium on Precision Medicine 

This paper is the first in Mayo Clinic Proceedings Symposium on Precision Medicine, a series of articles that will cover a wide range of topics in personalized medicine. Watch for upcoming articles in the symposium which will focus on how personalized medicine and genomics are impacting patient care in areas, such as oncology, rheumatology, neurology, gastroenterology, cardiology and pharmacology.

In each article, experts in their fields will:

• Review the state-of-the-art of the science.
• Discuss controversies in research and practice.
• Provide insights into how advancements in personalized medicine and genomics are transforming the medical practice.

Learn more about the Precision Medicine series.

Noralane Lindor, M.D., is professor of Medical Genetic, Department of Health Sciences Research at the Mayo Clinic campus in Scottsdale, Arizona, and Mayo Clinic Center for Individualized Medicine in Rochester, Minnesota.

Stephen Thibodeau, Ph.D., is the David F. and Margaret T. Grohne Director, Mayo Clinic Biorepositories Program, Center for Individualized Medicine, and the William H. Donner Professor of Laboratory Medicine and Pathology at the Mayo Clinic campus in Rochester, Minnesota.

Wylie Burke, M.D., Ph.D., is professor in the Department of Bioethics and Humanities, adjunct professor of Medicine (Medical Genetics) and Epidemiology, Fred Hutchinson Cancer Research Center, University of Washington in Seattle.

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Tags: #disease predictors, #Dr. Noralane Lindor, #Genetic data, #Genetic diseases, center for individualized medicine, DNA Testing, Dr. Stephen Thibodeau, Genetic Testing, mayo clinic, medical research, Uncategorized, whole genome sequencing