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Weighing the Benefits of Genetic Testing by Wenda Reed

Damaged, mutated and broken, abnormal genes run through the twisting strands of some people’s DNA, carrying messages for disease and disorder.

If we have one of those genes, would we want to know? Would it relieve our anxiety or confront us with a death sentence? Would it lead to early screening and bring better treatment options? Would it bring our families together or cause resentment and stress? Would it help us decide whether to have children if we are carriers of a genetic mutation? Would it ruin our chances of employment or mean we can’t get insurance? Would it affect our financial planning? Should we take that trip to Europe next year, rather than waiting?

A relatively small number of people have already confronted these questions. Many more of us will face them in the next decade. In a few years there may be another question: Can the mutated genes be manipulated by gene therapy to ward off the disease?

With the completion of the Human Genome Project in 2003, scientists have a picture of the 20,000– 25,000 protein-coding genes in human DNA. They have identified a few that are linked to specific diseases. Some of them are “determinate,” meaning that if we have the gene, we will get the disease. Others are “indeterminate,” meaning that if we have the gene, we have a greater chance of getting the disease than do members of the general population, but that we may never get it.

Presently there are genetic tests for hereditary forms of breast, ovarian and colon cancer, for a small fraction of Alzheimer’s disease cases, for hereditary neurologic disorders, such as Huntington’s disease and Muscular Dystrophy, for an iron overload disorder, for cystic fibrosis and for rare syndromes with multiple cancers.

However, the number of diseases scientists are linking to damaged genes “is increasing every year, month by month,” says Dr. Thomas Bird, chief of the Division of Neurogenetics at the University of Washington School of Medicine.

Just in the first few months of 2009, scientists announced a new test to determine the risk of recurrence of colon cancer, as well as the discovery of two mutations that appear to predict an increased risk of thyroid cancer. A new genetic test can determine the proper dosage of the blood-thinning drug warfarin. And in five years, researchers believe there could be a genetic test to predict a high risk of heart attack.

MAKING THE CHOICE TO TEST

Three local women have already faced the issues raised by genetic testing. They were recently tested for the BRCA (Breast Cancer) 1 and 2 genes, one of the earliest genetic links discovered, and a strong predictor of both breast and ovarian cancer.

Between 5 and 10 percent of women with breast cancer have hereditary risk factors. A strong family history of breast or ovarian cancer and a young age of onset are indicators that a cancer may be hereditary, says Robert Resta, a genetic counselor at the Swedish Cancer Institute’s three-year-old Hereditary Cancer Clinic. People in certain ethnic groups, especially Eastern European Jews, have cancers that are more likely to be hereditary.

“I was very against them (my sister, mother and aunt) getting the testing at first,” says Whitney Rhodes, a 24-year-old entrepreneur from Tacoma who does not have cancer.
As a child, Rhodes remembers seeing her mother, then 45, going through chemotherapy for ovarian cancer and losing her hair. She knew that her grandmother had died of ovarian cancer at age 45 and that her great-grandmother had also had the disease.

Rhodes’ sister promoted the idea of genetic testing, and it may have saved her life. After testing positive for the BRCA1 gene, she had a mammogram at age 31, was diagnosed with a small breast cancer tumor, and had a mastectomy. Rhodes’ mother and aunt also tested positive for the same gene and had prophylactic (preventative) mastectomies.

By that time, Rhodes was convinced that she should get tested. “I actually had a fear of it coming back negative. I would think, ‘Why did I get so lucky?’” she remembers. “On the other hand, it can be quite terrifying. I tend to be a positive person, but still …”

The test came back positive. It isn’t determinate — it does not guarantee that Rhodes will get the disease — but it does mean she has an 80–90 percent chance of having breast cancer and a 60 percent chance of having ovarian cancer over her lifetime. She has already had MRIs and will have her first mammogram this year. She has an annual physical exam for ovarian cancer. She travels from Tacoma to Seattle four times a year for preventative cancer care.

“We are all bonded together” by the family’s positive test results, Rhodes says. Still, “it’s not an easy thing to know,” she admits. “For the first few months, I thought about it every day. I would look down at my breasts in the shower and think, ‘They’ll have to take them off sometime.’ I know I will have to have a hysterectomy once I’ve had children. It’s a burden to bear and bring into a relationship.”

Heather Bakstad, a 34-year-old Seattle realtor and massage therapist, is still in treatment for stage I breast cancer. The form is triple negative, meaning that the tumor does not have receptors for estrogen, progesterone or the HER2/neu protein. It is an aggressive form of cancer, more common to younger women, less responsive to standard treatment and more likely to be hereditary. Her doctor thought there was a 99 percent chance the cancer was hereditary, and Bakstad was glad to get the test.

It was negative. “It was shocking,” Bakstad says. “I would have done a mastectomy for sure on both breasts. It does mean I have a better outcome and prognosis because the test was negative.”

She calls herself a “huge advocate” for genetic testing. “I would think you’d want to know so that you can plan,” she says. “I feel that you should get it if you have family members with the disease, especially if you’re young. You can be more religious with testing and screening.”
She has found some resistance among friends, partially because they are afraid of discrimination. “Everyone wants to do the ostrich thing,” she says. “People fear death.”

“I don’t come from a place of fear,” says Sarah Thompson, a 41-year-old Seattle human resources administrator with a 19-year-old son. She was diagnosed with triple negative breast cancer three years ago, and heard about genetic testing at a support group. Her mother is also a breast cancer survivor, giving her enough reason to be tested. “I wanted to know so that I could make plans,” she says. “I have nieces, and wanted to inform the family.”

Nevertheless, her oncologist was against the idea. “‘What would you do with the knowledge?’ he asked me. He was kind of horrified by the thought of younger women having prophylactic surgeries.”

Her test was also negative. “It means I don’t have to make another decision about removing my breasts,” Thompson says. “They’re still discovering genes, so there may still be a hereditary component.”

SHOULD YOU HAVE A GENETIC TEST?

There are three main reasons for genetic testing in adults, according to the National Institutes of Health:

• To find out if you carry a gene for a disease you might pass on to your children
• To test for genetic diseases before you have symptoms
• To confirm a diagnosis if you already have disease symptoms.

Most kinds of cancers — including lung cancer and leukemia — do not yet have reliable genetic markers or good means of early detection, says Resta, who has been a genetic counselor for a decade. “Testing for things we can’t do anything about is not necessary,” he adds. “Does the finding of the hereditary gene affect the treatment of the person? If not, why test?”

“For BRCA1 and 2, four other breast cancer mutations and colon cancer genes it does matter,” he says. Having the hereditary genes drastically increases the risk of breast and ovarian cancer, so MRIs and more screening are necessary sooner. “The implication is that you have your ovaries out by age 40.”

If you test positive for any of five gene mutations related to colon cancer, “you join the once-every-year colonoscopy club,” Resta says. You would also be screened for cancers of the stomach, uterus and kidney, which seem to be linked to the same genes.

Many patients consider genetic testing for their family’s sake, Resta says. “Even if you don’t have a daughter, you may consider screening because having the mutations can increase chances of a son passing them on to grandchildren.”

The National Cancer Institute notes that in some cases, there may be lifestyle changes people can make or drugs they can take to reduce the risk of contracting the disease, or to delay or even prevent its onset. Other tests can determine the optimal dose of certain drugs based on genetic profile.

Dr. Bird screens for more than 100 neurological diseases that are genetically linked. The main reason for getting a genetic test for a determinate gene mutation — one that guarantees you will get the disease — is to relieve anxiety, he says. “For most people, knowing is better, and they’re more comfortable. Sometimes people regret it, but most people cope very well.”
A second reason is for family planning — deciding if and when to have children. Career, financial and travel plans may also enter into the decision.

Genetic counselors and cancer experts emphasize that a negative test for a genetic marker does not mean you will not get the disease — it simply means that your chances are no greater than those in the general population.

SHOULD YOU PASS ON HAVING A TEST?

Bird agrees with Resta that if “you can’t do anything about it anyway,” there’s no good reason to have a genetic test.

A case in point is Alzheimer’s disease. Most instances of Alzheimer’s disease do not have a hereditary component. However, if you have several family members who had early onset Alzheimer’s (occurring before age 60), a person with the disease can be tested to see if they have a mutation on one of three specific genes. If a parent has one of those mutations and has Alzheimer’s, each child has a 50 percent chance of having the mutation. If you have the mutation, you will get the disease.

A fourth gene is linked with the more common form of Alzheimer’s, which begins to show symptoms in old age. People with one copy of the gene have a greater risk of Alzheimer’s than does the general population, and people with two copies — from both parents — have an even greater chance. However, the test is “neither necessary nor sufficient” to predict the disease,” Bird says. It indicates a higher risk factor, but even if you have the gene, you may never get Alzheimer’s.

“Frankly, right now there’s not much you can do about Alzheimer’s,” notes Nancy Dapper, executive director of the Alzheimer’s Association, Western and Central Washington State Chapter. “There’s no intervention to dramatically reduce the risk of developing it. I don’t see the point of genetic testing for it.”

The decision to get genetic testing can cause friction in families. “In some cases among siblings, one decides to be tested and one not,” Bird notes.

Having a positive result on a genetic test “can make people very depressed,” Bird says. “They feel doomed; they give up.” Although he has never refused to do a genetic test for someone, he and genetic counselors on his team do screen patients to determine their feelings. They may recommend that a patient meet with a psychiatrist to talk through the issues before she gets the test.

Resta recommends that people considering genetic testing meet with a certified genetics counselor, with a master’s degree in the field, to review medical and family history, to follow up on results, and to make decisions about testing other family members. “We need to be alert and aware and sensitive to emotions,” Resta says. “The human component (of testing) is as interesting as the genetic component.”

Wenda Reed is a Seattle-area health writer and frequent contributor to Seattle Woman.

WHAT ABOUT THE FINANCIAL COST?

The cost of genetic testing under medical supervision ranges from several hundred to several thousand dollars.

In many cases it will be covered by insurance, especially if the test results will affect the person’s screening and treatment decisions. Resta recommends checking with your insurance company before applying for the tests. In some cases, when the reason for testing is to help make decisions about family planning, the insurance companies may not pay, Bird says.

The National Cancer Institute notes that some people may not want to use their insurance company to pay for genetic testing because they fear it may affect their health insurance. To protect their privacy, some may not even want their insurer to know they are thinking about genetic testing. The results of a genetic test will usually become part of the person’s medical record.

When applying for medical, life or disability insurance, people may be asked to sign forms that give the insurance company permission to access their medical records. The insurance company may take genetic test results into account when making decisions about coverage.The passage of the federal Genetic Information Nondiscrimination Act in May 2008 will relieve some of those worries. It prohibits group health plans and health insurers from denying coverage to a healthy person or charging her higher premiums based solely on a genetic predisposition to developing a disease in the future. It also bars employers from using genetic information when making hiring, firing, job placement or promotion decisions.

The act does not cover life, disability or long-term care insurance. Although Resta believes insurance companies usually don’t ask about genetic testing, he advises patients to “get your insurance ducks in a row” before having the tests.

The Alzheimer’s Association has issued principles intended to prevent genetic discrimination, including a provision that the presence of a gene associated with Alzheimer’s should not be used to deny access to housing, employment, health care, insurance or any other goods or services. It advises that anonymous testing should be available to make the fact of and results of genetic testing invisible on an individual’s medical record.

©2009 Caliope Publishing Company