March 24, 2014

With genetic testing, patients can see the future

The human genome was mapped in 2003, revealing for the first time the entire genetic makeup of our bodies. Since then, genetic testing has become a booming industry, but is it right for you?

Denis Keegan was out of answers.

The 30-year-old was suffering from kidney disease, but his doctors were struggling to pinpoint the cause. That’s when Keegan turned to genetic testing.

Doctors at the Mayo Clinic in Rochester, Minn., extracted his DNA from a blood sample and examined his genome. There, embedded in his genetic code, they discovered the source of his kidney problems – a mutant gene. The finding led them, at last, to a diagnosis: fibronectin glomerulopathy, an extremely rare kidney disorder. Armed with that knowledge, his doctors were able to tailor treatment for the condition.

“It was really reassuring,” said Keegan.

The human genome was mapped in 2003, revealing for the first time the entire genetic makeup of our bodies. Since then, genetic testing has become a booming industry – and an option for patients, such as Keegan, to learn more about their bodies’ internal mysteries.

Advancements in the testing are coming rapidly, slashing the price and time it takes to get results. Just as the X-ray machine made it possible to peer inside the human body, genetic testing is changing the way we diagnose and treat diseases.

Testing is available through your doctor, or increasingly via direct-to-consumer kits that can be ordered online or purchased at a drugstore. By the end of the decade, Americans are expected to spend as much as $25 billion a year on genetic tests for everything from diagnosing types of kidney diseases to determining breast cancer risk to screening prenatal health, according to UnitedHealth.

But for some patients, genetic testing represents a Pandora’s box that, if opened, could cause needless anxiety among healthy people or sow discord in families if one member’s test reveals troubling findings about the family’s genetic makeup.

To help navigate this brave new world, we turned to those on the front lines of this fast-evolving medical technology:

•  What is genetic testing?

Genetic testing typically involves looking at a person’s genes or chromosomes to help prevent, diagnose or treat a disease. It also can be used to determine whether a person is a carrier of a genetic disease and if there is a risk of passing it on to his or her children. Most often, the testing begins with DNA collected from a blood sample, but many labs also can get DNA from a person’s saliva.

•  How much does it cost, and does insurance cover it?

The cost varies widely, from $99 at-home kits (such as the controversial 23andMe) to thousands of dollars for tests conducted at hospitals and clinics. Pricing also varies depending on what you are testing for, such as a newborn screening or colon cancer.

Insurance coverage also is dictated by the kind of testing and the individual’s plan. Typically, insurance companies will cover tests that are ordered by doctors and usually involve diagnosing a disease. Patients who have a significant family history with a particular disease tend to receive coverage.

Direct-to-consumer genetic test kits are not covered. Hundreds of thousands of people have used 23andMe, which analyzes a segment of a person’s DNA sequence for genetic alterations linked to cystic fibrosis, sickle cell anemia and even breast and ovarian cancer. But critics – including the U.S. Food and Drug Administration – say the test is limited in its ability to diagnose health risks accurately and could lead users to undergo unnecessary medical procedures. FDA officials recently ordered 23andMe to halt marketing its DNA test kits.

•  What can a test reveal?

For someone with a defined disease, the use of genetic testing can be very effective in determining what medicines work best in treatment, doctors say.

A 44-year-old woman with gall bladder cancer is among the success stories at the Mayo Clinic’s Center for Individualized Medicine, said Dr. Alexander Parker, the center’s associate director. Her tumor was not responding to the standard medicine used to treat gall bladder cancer. Through genetic testing, doctors discovered that drugs used on leukemia patients might work for her. They tried it, and her tumor started to shrink, Parker said.

But for healthy people, whom he calls the “worried well,” there is little to no value in having your genome mapped. It may cause harm by raising anxiety about the odds of developing a disease.

•  What factors should go into your decision to get a test?

Parker encourages those curious about genetic testing to have a conversation with their primary doctor first. Ask: “Is there any value in this for me?”

Genetic counselors also play a key role in helping reach a decision. They typically hold master of science degrees in programs that include training in medical genetics and counseling. They work in consultation with doctors, nurses and other health professionals.

Truelson said she encourages patients to ask these questions: What type of information will the test give me? How will this affect me from a medical standpoint? How will this affect me from an emotional standpoint?

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