In 2017, the number of genetic tests given in America more than doubled from past years. The spike in testing was traced to heavy marketing of the new do-it-yourself DNA testing kits, which let people take a closer look at their family history.
Many of those at-home kits are new, but genetic testing has been used in health care since the 1950s. Today, genetic tests can help doctors catch more than 2,000 health conditions. That’s why it’s no exaggeration to say that this view of the DNA we all get from our parents and grandparents can save lives.
Genetic testing involves taking a sample of your genes from your blood, tissue or saliva and testing it in a lab. The results allow doctors to pinpoint the diseases you are at an increased risk of developing.
For example, if your mom, aunts or sisters had breast or ovarian cancer, you may be at risk. That’s because cancer is one disease that can run in the family. With genetic testing, doctors can now tell you how much a risk you have.
A Big Family’s Big Problem
Blue Cross and Blue Shield member Erin Bley comes from a big family. Her mom was one of nine children, and she has three sisters and several cousins.
After an aunt was diagnosed with stage 4 ovarian cancer at age 39 — the same cancer Erin's grandmother had died from at 52 — she and another aunt sought advice from a genetic counselor.
Their worries about the risk soon became fact. They tested positive for the BRCA1 gene mutation, placing them at high risk for breast, ovarian or uterine cancers. The results led them to encourage others in the family to get tested.
“The more we know, the more we can do,” Bley said.
Since that time, Bley has had a series of blood tests and imaging every six months. During one of those exams, doctors found a mass in her breast. Though it wasn’t cancer, she decided it was time to act. So at age 40, Bley had a full hysterectomy and double mastectomy.
Preventive surgery is one option women are considering more than ever for breast, uterine and ovarian cancer. And your health insurance may cover it if genetic testing shows a high risk.
Knowing what your genes say about your health helps you decide what to do about it, Bley said. “It was a gift that I had a choice. I could be in charge of what I wanted my experience to be.”
Just Your Type
There are many types of genetic tests, and they tell doctors different things. They include tests that can:
- Identify what is making a person ill
- Predict a person’s chance of developing a disease
- Let people know if they “carry” a genetic change they can pass on to their children
- Help identify problems an unborn baby may have
- Determine if an embryo for in vitro fertilization carries genes that could cause disease
- Screen newborn babies for certain problems with health and development
- Find the best drug for treating an illness
How It Works
Genetic testing is relatively easy for all but embryo and fetus testing. Most other screenings involve a simple sample of blood, hair or skin. You can also do a saliva swab.
Doctors can check for birth defects by testing the amniotic fluid, the fluid around an unborn baby, and the placenta, the organ that feeds the fetus. Those tests are more invasive, since the sample comes from within the mother’s body.
After a sample is gathered, it is sent to a lab where technicians check for mutations, or changes, in the genes, depending on the disease or disorder being tested. The lab sends the results to the doctor or a genetic counselor, who can then form a plan for addressing the results. The results can also be sent directly to the patient.
The Benefits and Drawbacks
The best thing genetic testing may give you is peace of mind. While the results may not be what you wanted, it can help to know what your future holds. Armed with information, you and your doctor may be able to catch problems before they become serious.
Risks of genetic testing are low, but there are some. For instance, there is some risk of miscarriage from the testing of unborn babies.
And testing can take an emotional toll on you and your family. Genetic testing can also be expensive. If you test positive for an inherited condition, the costs of preventing the illness can quickly add up.
Finally, some disorders don’t have a clear and effective treatment. Unfortunately, knowing you’re at risk of developing a health problem doesn’t always mean you can do anything to prevent it.
It’s important that you weigh the risks and benefits before you begin genetic testing for medical reasons. A talk with a genetic counselor may help. Your doctor can refer you to one.
Talk to your doctor.
You’ll be asked about family history of illness as part of the paperwork you fill out during a doctor’s visit. If you have a family history of a serious illness, ask your doctor if genetic testing is right for you. Only you can decide if you want to know what the future may hold.
Sources: 2017 was the year genetic testing blew up, MIT Technology Review, 2018; Genetic Testing, Medline Plus, U.S. National Library of Medicine; Genetic Testing: How it is Used for Healthcare, National Institutes of Health, 2013; What are the risks and limitations of genetic testing?, What disorders are included in newborn screenings? Genetics Home Reference, U.S. National Library of Medicine, 2018; Prenatal Tests, March of Dimes, 2017; Common Tests During Pregnancy, Johns Hopkins Medicine Health Library