Genetic testing can warn of medical issues

But doctors say you can’t rely on Ancestry or 23andMe.

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Dr. Terry Kriedman, center, shown here at a cannabis forum back in March, is an obstetric/gynecological specialist and does gene mutation testing that indicates potential for diseases. — Gabrielle Mannino

There is “genetic testing,” and then there is genetic testing.

Spitting into a tube and sending your sample off to ancestry.com or 23andMe, it may take two months to learn the results. Depending on the details you are seeking, and the cost you are willing to pay, you learn a varying amount about your family history or heredity.

For example, Sue Hruby of West Tisbury learned that in addition to being 100 percent European, “I have 85 percent more Neanderthal than other 23andMe participants. That always gets a good laugh and some knowing smiles.”

A customer service representative at ancestry.com told The Times that its form of genetic testing only tells the subscriber what region of the world ancestors came from.

The 23andMe program, according to its website, offers two levels of research — ancestry ($99) and health and ancestry ($199). The “health and ancestry service” offers five reports: BRCA1/BRCA2 (the genetic mutation that signals the potential for breast and/or ovarian cancer), celiac disease, late-onset Alzheimer’s disease and Parkinson’s disease. According to the company’s recorded information, the report a customer receives ”is not intended to diagnose any condition or to tell you about your risk or your child’s risk for developing a condition.” A request by The Times for an interview with a 23andMe representative was denied.

When healthcare professionals use the term “genetic testing,” they are focused on evaluating health risks. For example, medical genetic testing evaluates if you are at low, medium, or high risk of breast cancer, ovarian cancer, prostate cancer, or colon cancer.

Dr. Terry Kriedman, an obstetric and gynecological specialist on the Island, primarily tests patients for the BRCA1 and BRCA2 gene or mutation. “What medical genetic testing is doing is looking for genetic diseases or genetic mutations, with the idea that if somebody tests positive there are proactive things that can be done,” Dr. Kriedman explained.

Before any testing is undertaken, Dr. Kriedman said a physician will spend time with a patient recording a family history, and counseling on what may or may not be learned through the testings. If genetic testing seems appropriate, Dr. Kriedman collects a saliva sample from inside the cheek, which is sent to an off-Island laboratory for analysis.

“My typical patient is a woman whose focus is on genetic testing for mutations that increase the risk for breast, ovarian, colon, and uterine cancers. What I test for is inherited cancers or an inherited propensity for cancer,” she said.

If a patient is able to trace her family history back several generations and there are or were relatives known to have had cancer, this helps a physician understand, and explain to a patient, the level of concern or risk. For a patient with no history of breast cancer in her family (siblings, aunts, grandmothers, for example), the risk is low, and she may decide against testing. For patients with a greater risk, or a high risk, testing is recommended.

Should the genetic testing results show the BRCA mutation, the cost of the testing is usually covered by insurance. “I have not had anyone be refused coverage by their insurance company,” Dr. Kriedman said.

With the test results in hand, a patient and physician will discuss the results and the “next steps,” if any are indicated. The test results may come back indicating little or no risk of breast or ovarian cancer.

A low-risk test result may mean increased surveillance through annual mammograms or breast MRIs, and modifying behavior by decreasing alcohol consumption, not smoking, or losing weight, for example. Patients with high-risk test results may decide to have bilateral mastectomies, their ovarian tubes and ovaries removed, and/or to take drugs to suppress estrogen in the breast.

“In the general population, the risk of breast or ovarian cancer, for example, is low. If there is a familial history of breast or ovarian cancer, the risk level is moderate, and if you test positive for the genetic mutation, your risk is high,” Dr. Kriedman said.

“It is important to point out that only about 8 percent of the male population tests positive for the BRCA mutation, but men who test positive have significantly higher risk for pancreatic or prostate cancer,” she added.

Dr. Jim Weiss of Oak Bluffs is in his early 70s. When his father was in his 50s, he had a mastectomy to treat breast cancer, and lived well into his 90s. Dr. Weiss has been aggressive about medical checkups, lab tests, and biopsies since his early 50s. While his prostate gland continues to enlarge and his PSA (prostate-specific antigen) test results are way above normal, there are no signs of cancer. About five years ago, he discussed genetic testing with his medical specialist, and was told that it would cost him $5,000. Dr. Weiss declined to be tested.

Jill Stopfer, associate director for genetic counseling at the Dana Farber Cancer Institute, told The Times that clinical or medical genetic testing is performed for three reasons: to identify prenatal risks, diagnostic evaluation, and/or to determine susceptibility for cancer and other diseases. “Genetic testing is really lifesaving. It helps you and your family proactively deal with many health conditions,” she said.

According to Stopfer, most genetic testing is done to determine prenatal issues (about 40 percent) and cancer risks (40 percent), with other, rarer diseases being tested for about 20 percent of the time.

Prenatal genetic testing may be indicated because the woman knows that there is a genetic probability based on family history and “pan-ethnic testing” when the woman and her partner may unknowingly carry recessive genes that are disease carriers. Whether tested before becoming pregnant or when already pregnant, genetic testing offers the patient a “lot of tools in the tool kit” to reduce risks.

“Genetic testing is far more affordable than it ever was,” with the cost now ranging from as little as $100 (depending on insurance and income), according to Stopfer. And Stopfer warned that “direct consumer testing” (such as ancestry.com and 23andMe) is not “clinical, medical genetic testing.”

“These companies are working with third-party clinics to interpret the samples, and the results are inaccurate 40 to 50 percent of the time,” she said. “This is not benign.”