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Genetic testing a healthcare option

By Staff | Sep 13, 2008

Genes, made from the twisting DNA structures, carry the secrets to what will happen to our bodies as we get older. All it takes is a simple test using a cotton swab of saliva or a dab of blood to unlock our genetic futures.

And while genetic manipulation is still left for the creators of science fiction, genetic testing is very much a reality.

The popularity of this type of testing has been spreading across the United States, peaking interest into finding what secrets lie hidden in our own genetic codes and affording patients the opportunity to discover if they are prone to cancer, heart disease or Type 2 Diabetes.

“They can get information about their own health and the health of their family,” said Diane Allingham-Hawkins, director of the Genetics Test Evaluation Program in Pennsylvania. “That is the kind of information we are starting to be able to get and there is a lot of potential.”

At the heart of genetic testing is human nature and how patients choose to use this genetic knowledge.

Doctors can tell patients what to do to prevent disease but it’s not enough. If a patient is told they are at a high risk of heart disease, for example, would they actively choose to change their diet and exercise or continue to eat poorly?

Even if genetic testing can relatively “foresee the future,” medical experts state it still depends on the patient to do everything they can to prevent what may be inevitable.

Genetics and DNA were only discovered 50 years ago and since then, scientists have been identifying and defining new genetic codes associated with health problems — such as breast cancer, cystic fibrosis or sickle-cell anemia.

“The breast cancer test indicates that if you carry one of those genes there are things you can do about it,” said Allingham-Hawkins.

The American Cancer Society reported this year that 178,480 women and 2,030 men were diagnosed with breast cancer in 2007. Each of these patients carried one of the genetic markers indicating they’re at a higher risk of developing this type of cancer (BRCA1 or BRCA2).

Of course, the reliability of these tests can vary depending on what condition or disease is being studied in a genetic code. A patient with a genetic variant indicating Huntington’s Disease, for instance, would have a 100 percent chance of developing it in their lifetime. On the other hand, a person carrying a mutated gene could live their entire life without ever developing cancer.

Genetic counselors at Lee Cancer Care study genetics associated with cancer and provide patients with an assessment.

They use genetic testing to determine if a patient is likely to develop breast or ovarian cancer from the BRCA genes, but they also create a family tree of the patient that dates back three generations.

“People can use tests to make medical decisions, prevent cancers or for early detection,” said Cindy Merrill, a genetic counselor at Lee Cancer Care.

Merrill, who administers 150 to 180 genetic tests a year, said that more people are choosing to undergo these tests.

She said a 70-year-old woman who carries the BRCA gene has a 56 to 87 percent chance of developing breast cancer in her lifetime, and a 28 to 44 percent chance of carrying ovarian cancer.

“Genetics is a very young study. There are a lot of things we don’t know about it and a lot of genes that haven’t been discovered,” said Merrill.

This year, in response to the increasing use of genetic testing across the nation, the federal government passed the Genetic Non-Discrimination Act of 2008. It prevents health insurance companies from denying coverage to people who have had genetic tests and report a higher chance of developing a particular disease.

“GINA eliminated fears that people had that if they have a test showing they have a predisposition to something that they will be declined health insurance,” said Allingham-Hawkins.

The new law is a step forward to ensuring fair health care for people who have completed genetic testing, but GINA still doesn’t include members of the military or cover people seeking life insurance, disability insurance or long-term care insurance.

Further, the increased availability of genetic tests has spawned a market where people can participate in “recreational genetic testing,” allowing patients to order personal testing kits from various Web sites.

These kits are mailed directly to a person’s house and some officials say they are dangerous because they take out the most important element in disease assessment – the doctor.

Furthermore, federal oversight of genetic home kits hasn’t caught up with the market’s saturation.

Allingham-Hawkins said that the science behind these kits is weak and patient assessments could vary by as much as 20 to 40 percent.

“These companies are interesting at best but scary at worse,” she said. “If you had a result suggesting you are at low risk for breast cancer, and you say you won’t get mammograms, that is not a good a idea.”

She said that the future of genetics exist in pharmacogenetics, a science that uses a patient’s genetic make-up to determine which prescription would most benefit and eliminate side-effects.