Routine DNA screening moves into primary care

May 22, 2018

If you have a genetic mutation that increases your risk for a treatable medical condition, would you want to know? For many people the answer is yes. But typically such information has not been a part of routine primary care.

For patients at Geisinger Health System, that could soon change. Starting in the next month or so, the Pennsylvania-based system will offer DNA sequencing to 1,000 patients, with the goal of eventually extending the offer to all 3 million Geisinger patients.

The health system’s test will look for mutations in at least 77 genes. Many have been associated with medical conditions—dozens of them, ranging from heart disease to cancer. Others have been linked to variability in how people respond to certain medicines based on heredity.

But some physicians and health policy analysts question whether such genetic information is necessary to provide good primary care and whether handling such testing is feasible for many primary care physicians.

The new clinical program builds on a research biobank and genome-sequencing initiative called MyCode that Geisinger started in 2007 to collect and analyze its patients’ DNA. That effort has enrolled more than 200,000 people.

Like MyCode, the new clinical program will be based on “whole exome” sequencing, analyzing the roughly 1% of the genome that provides instructions for making proteins, where most known disease-causing mutations occur.

Using this analysis, clinicians could tell Geisinger patients whether or not they have a genetic variant associated with Lynch syndrome, for example, which leads to an increased risk of cancer of the colon and some other cancers. Or doctors could offer guidance to patients found to have an increased risk for familial hypercholesterolemia, which can result in high cholesterol levels and heart disease at a young age.

Still other patients who undergo the exome sequencing might learn they have an increased susceptibility to malignant hyperthermia, because of a gene variant that causes a severe reaction to certain medications used during anesthesia; the reaction can be fatal.

Geisinger spokesperson Wendy Wilson says that what the company plans is very different from direct-to-consumer services like 23andMe —which tests customers’ saliva to determine their genetic risk for several diseases and traits, only some of which are medically actionable, and makes the results available in an online report.

“Geisinger is prescribing DNA sequencing to patients and putting DNA results in electronic health records and actually creating an action plan,” Wilson says. “We are preventing disease from happening.”

Geisinger says its program will work like this: Samples of a patient’s blood or spit will be used to get a DNA sample. After analysis, the results will be sent to the patient’s primary care doctor.

The doctor will then take a 30-minute online continuing education tutorial to review genetic testing, and get more information on whatever specific susceptibilities have turned up in that patient’s results.

After that, the patient will be informed and invited to meet with the primary care provider, along with a genetic counselor if desired. At that point the doctor and patient can discuss treatment and prevention options, including any particular lifestyle changes that might reduce the risk of developing the disease or condition.

About 3.5% of the people who have already been tested through Geisinger’s research program had a genetic variant that could result in a medical problem for which clinicians can recommend helpful steps to influence their health, Dr. David Feinberg, Geisinger’s president and CEO says.

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