What drives some to get genetic test?

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March 31, 2014 | 5:35 pm

IOWA CITY — With one mouse click, Jeff Murray could find out how likely he is to get Alzheimer’s disease, a form of dementia that slowly destroys memory and thinking.

The University of Iowa pediatrician, known for his work on cleft lip and cleft palate deformities, paid about $200 and submitted a vial of saliva for a genetic test.

Scientists first mapped the human genome in 2003. Online genetics labs, like 23andMe, Navigenics and deCODEme, now have made it possible — and affordable — for the common person to learn about his or her own DNA.

Some people, like Murray, are doing it because they are curious. He also teaches medical students about the tests and wanted a direct understanding of what they do.

Other people want to know whether they carry a genetic mutation for a disease that has wreaked havoc on their family for generations. The more you know about proven predispositions, the more you can do to protect yourself and your progeny against disease.

How much do we want to know, though?

Murray’s genetic profile, which he can pull up on the Internet, shows his risk, compared to the general population, of developing a host of diseases and medical conditions.

Like gout. Murray is genetically predisposed to the uric acid imbalance that can cause inflammatory arthritis in the feet. He’s already been diagnosed with gout, but now he knows his genes are partly to blame.

Murray has chosen not to learn whether he has genetic mutations that cause early-onset Alzheimer’s or Parkinson’s disease.

“I haven’t looked at either of those because my family doesn’t want me to,” Murray said. “If I have (the mutations), there’s something like an 80 percent greater chance that I’ll get (the diseases), whereas most of the other risks are much smaller.”

Amanda Goodlove, a 29-year-old mother and first-grade teacher from Lisbon, had the test because “I felt it was important for me to find out for me and my children.”

Goodlove found out in 2010 that her 30-something cousin had breast cancer. Other women in the family also had been hit with the disease early in life. Goodlove decided to get a genetic test to see if she had a mutation of the BRCA1 gene, which increases susceptibility to early-onset breast cancer.

“We have two boys, but we would like a third (child),” Goodlove said. “Had I found out I had the gene, I don’t know that we would have a third. I don’t know that I would pass that on.”

After waiting a week for the result of the blood test, Goodlove learned she does not have the mutation. “I cried,” she said. “It’s pretty emotional whether you have it or not.”

Steve Groner, 53, of Tipton, spent four years thinking about whether he wanted to know if he carried the gene mutation that contributed to the ovarian cancer that killed his sister. On one hand, mutations of the BRCA2 gene would cause only slightly increased cancer risks for Groner. On the other hand, knowing whether he had the DNA marker could mean passing on valuable information to his female descendants.

“I decided to see if the disease continues to carry on for my granddaughters,” Groner said.

Women who have either of these mutations, which are markers of increased risk for a variety of cancers, may choose to get earlier mammograms or decide to have children early and then get a complete hysterectomy to reduce their chances of getting ovarian cancer, he said.

Groner’s genetic test showed he has the BRCA2 gene mutation. It will be up to Groner’s sons and granddaughters, now ages 3 and 6, to decide in future years whether they want to know if they, too, carry the DNA marker.

Not everyone is ready for what they might learn through genetic testing, said Julie Thompson, a nurse practitioner who counsels people about cancer risks for St. Luke’s Hospital in Cedar Rapids.

“It’s a huge decision, and there are a lot of ethical concerns that go with that,” Thompson said.

Thompson works with people who have been diagnosed with cancer and people who have a family history of cancer and want to know if they have an increased genetic risk of the disease. She asks her patients:

l Why do they want to be tested?

l What is their true family history?

l What do they plan to do with the information that comes from the genetic test?

Thompson also gives them the cruel truth: Even if they don’t have genetic markers for cancer, they can still get it.

“Seventy percent of cancer diagnoses are sporadic and have nothing to do with genetics,” she said.

Knowing about genetic predispositions for cancer can help patients get preventive health care, like earlier mammograms or colonoscopies. Sometimes insurance companies require genetic tests to approve the earlier treatments.

Some diseases don’t have preventive measures. The Alzheimer’s Association reports on its website that three genes have been found to cause or have links to the early-onset form of Alzheimer’s, which is, thus far, incurable.

These incidents of early-onset Alzheimer’s are rare and are fewer than 1 percent of all cases, the association reports.

Murray is concerned people will see “decreased risk” for specific diseases and may not watch out for trouble signs, like irregular moles that might be skin cancer. Just because your genes say you have a lower risk of heart disease doesn’t mean you can dine exclusively on doughnuts and beef sticks without repercussions.

“Genetics don’t determine who or what you are,” he said.

Murray believes it’s too late to put the genetics genie back into the bottle, even for online tests that don’t come with genetic counseling. He hopes people will seek advice — ideally before testing — from a health-care professional who can help them understand the tests and what they might reveal.

Comments: (319) 339-3157; erin.jordan@sourcemedia.net

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