ó Denis Keegan was out of answers.
30-year-old was suffering from kidney disease, but his doctors
were struggling to pinpoint the cause. Thatís when Keegan
turned to genetic testing.
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 ó 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.
was really reassuring," said Keegan, 30.
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 ó and an option for
patients, such as Keegan, to learn more about their bodiesí
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.
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.
some patients, genetic testing represents a Pandoraís box
that, if opened, could cause needless anxiety among healthy
people or sow discord in families if one memberís test
reveals troubling findings about the familyís genetic
terms of how we apply it to our health, thatís where the
door has just been opened," said Melissa Truelson, a
certified genetic counselor at the University of Minnesota
Medical Center, Fairview.
navigate this brave new world, we turned to those on the front
lines of this fast-evolving medical technology:
testing typically involves looking at a personís 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
their children. Most often, the testing begins with DNA
collected from a blood sample, but many labs also can get DNA
from a personís saliva.
testing jumped into the spotlight last year when Angelina
Jolie, whose genetic test revealed a high risk of developing
breast cancer, chose to undergo a double mastectomy in the
hopes of preventing the disease.
our body does functions off of genes," Truelson
explained. "When you think about diseases, many of them
have an underlying genetic or inherited basis to them."
does it cost, and does insurance cover it?
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.
coverage also is dictated by the kind of testing and the
individualís 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.
genetic test kits are not covered. Hundreds of thousands of
people have used 23andMe, which analyzes a segment of a personís
DNA sequence for genetic alterations linked to cystic
fibrosis, sickle cell anemia and even breast and ovarian
cancer. But critics ó including the U.S. Food and Drug
Administration ó 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.
a test reveal?
someone with a defined disease, the use of genetic testing can
be very effective in determining what medicines work best in
treatment, doctors say.
44-year-old woman with gall bladder cancer is among the
success stories at the Mayo Clinicís Center for
Individualized Medicine, said Dr. Alexander Parker, the centerís
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.
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
the end of the day, this is about risk," Parker said.
"While we all want definitive answers to everything, the
beautiful thing about our world is that there is random
chance. Because of that, we can never say 100 percent that we
know exactly what will happen to anyone."
factors should go into your decision to get a test?
encourages those curious about genetic testing to have a
conversation with their primary doctor first. Ask: "Is
there any value in this for me?"
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
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
Maalouli, of Eagan, Minn., has wrestled with these questions
for years. Her mother died of ovarian cancer before she
reached menopause. Her grandmother and an aunt on her motherís
side died of breast cancer. Maalouli worries she may be next.
A genetic test would tell her if she carries a mutant gene
associated with higher risks of breast and ovarian cancer.
agonized over the decision to get tested, in part because she
fears the test for breast cancer would be positive.
donít know if I can live with that," she said. "I
feel like maybe it will (make) me depressed."
visited a genetic counselor three times in the past 10 years
to weigh the pros and cons. At 51, she and her three sisters
ó all healthy so far ó have made a pact. They will get
regular mammograms and MRIs, and if any of them detects that
there is something wrong, then the sisters will all go in for
testing affect your family?
personís choice to get tested may also reveal health
information about your relatives, who may prefer not to know,
Keegan, who visited Mayo from Ohio, the decision to have his
genome mapped affected several members of his family. Mayo
doctors asked his older brother and father also to submit a
DNA sample to find out if Keegan had inherited his fatherís
disease. Keeganís father previously had a kidney transplant.
addition, Keegan and his wife were thinking about starting a
family and wanted to know what their chances would be of
passing on the mutant gene. Turns out there is a 50 percent
chance their offspring will inherit it. For the couple, the
test results have led to many discussions about having
talked about possibly taking a fertilized embryo and checking
it to see if it has the mutated gene before deciding to
continue with the pregnancy. "We stepped back, and
thought, ĎWeíre kind of playing God here,í" Keegan
said. "We didnít think we wanted to do that."
end, theyíve decided that when the time comes, theyíll
roll the dice and have children the old-fashioned way.
he passes the gene onto his child, thereís a good chance
that during the childís lifetime there will be medical
advancements to improve treatment of the disease, Keegan