| Perils and promise of DNA testing |
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In some cases, the Web site offering testing is a
lab; in other cases it outsources the testing to a lab or labs.
Labs that return test results to patients must be certified under
CLIA, the Clinical Laboratory Improvement Amendments, implemented
by the federal Centers for Medicare & Medicaid Services. You
may notice AABB, or American Association of Blood Banks, certifications
on some Web sites; the AABB is a separate certification process
for labs that handle blood.
While these certifications are one way to determine
if a lab is on the up and up, certification is only one indicator
of whether a particular test is valid.
"There really isn't much transparency with DNA
testing," says Gail Javitt, a policy analyst at the Genetics
and Public Policy Center of Johns Hopkins University. "There
is no way for a consumer to go and check if a Web site or lab is
certified for a particular type of test. The regulations haven't
caught up with the science."
Fees for DNA tests at labs that provide paternity,
relationship and other testing range from $200 to $500 for varying
levels of paternity and relationship testing to $330 for chronic
lung and liver disease, and more than $3,000 for certain breast
and ovarian cancer genetic tests.
Accuracy of tests
There are a few different ways scientists assess the accuracy of
tests -- including DNA tests.
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Accuracy assessments for genetic tests: |
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Any worthwhile DNA test run by a legitimate lab should
meet the first two standards. As for the third, consumers must decide
on their own whether they want to know the results of a test for
a disease when there is no currently available treatment or cure.
When consumers do get the results of online DNA tests,
there's the potential for a gap in understanding what those results
mean.
"I'm very concerned as to whether consumers will
understand the information they receive from a genetic test and
whether the test itself is clinically valid or useful in terms of
what a consumer can do with that information," says Gail Geller,
associate professor of pediatrics in genetic medicine at the Berman
Bioethics Institute of Johns Hopkins University.
Why test?
Whether to get a DNA test is a decision only you can make. In some
cases, knowledge can help you make better decisions. In other cases,
it might not be a good idea if there isn't anything proactive you
can do with the information.
"There are personal issues involved," says
Dr. Brandt Cassidy, director of laboratory operations for DNA
Solutions, a company that provides DNA testing in the human,
plant and animal market. "For example, with Huntington's disease
there is a test that reveals if you have two copies of the gene.
If you do, you'll get it and you'll be dead by the time you're 45
because there is no cure. This is where genetic counselors come
in because if you are going to get this kind of information you
need to be prepared."
However, if a test result you receive from a legitimate
lab reveals that you have a higher risk for certain types of breast
cancer, for example, there may be treatment options that you can
pursue to lessen the risk that you'll actually develop the cancer.
In any case, before you test, it is wise to consult with a genetic
counselor from the National
Society of Genetic Counselors. The NSGC database
provides a list of genetic counselors in the U.S. and around the
world.
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