Archive for Tuesday, May 6, 2008

Caution urged in choosing gene tests

May 6, 2008


— Everyone's genes spell out a risk for some disease, and a coming anti-discrimination law is about to give genetic testing a boost.

But discrimination is just one hurdle. The bigger quandary: Doctors don't yet know how many of the genetic tests being pushed for dozens of conditions are truly useful - and how many are misleading at best.

"Some of these tests are complete rubbish," warns Dr. Howard McLeod, a personalized medicine specialist at the University of North Carolina. "The big challenge for a consumer is figuring out which data is real or not without having to go to medical school."

President Bush is expected to sign into law federal protection against genetic discrimination, a bill barring employers and insurers from using test results against patients.

First to benefit will be people who put off learning if they inherited genes responsible for diseases that run in their families - breast cancer, colon cancer, Huntington's, early-age Alzheimer's - for fear of losing insurance coverage or a job.

No one knows how many people that encompasses. The National Institutes of Health estimates 30 percent of potential volunteers for gene studies cite discrimination fears in backing out. At the same time, states have adopted a patchwork of protections, and steadily growing use of two of the best-proven tests - for the BRCA1 and BRCA2 gene mutations linked to breast and ovarian cancer - suggests that lingering concern hasn't been a huge deterrent for people with strong family histories of disease.

But until now, most genetic testing has been for conditions linked to single genes gone wrong, typically rare ones.

Specialists advise anyone considering a gene test to:

¢ Consult a doctor or one of the nation's 3,000 genetic counselors, to weigh pros and cons.

¢ Ask what the results will mean for siblings or children. How big is their risk, and do they want to know?

¢ Ask how accurate the test is, and if knowing you've got a risky gene allows you to take steps for better health or just worry.

"It's not of value unless you're going to do something to modify your health behavior," cautions Angela Trepanier of Wayne State University, president of the National Society of Genetic Counselors.


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