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Should You Get a Genetic Test for Lynch Syndrome?

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It's no secret that one of the keys to beating many types of cancer is catching it early—and the best way to do that is to study up on your family history, taking note of any potential risk factors. And much like getting tested for the BRCA gene can help you be on the lookout for breast cancer, there's another cancer-causing genetic condition you may want to put on your radar. Its street name: Lynch syndrome.

What Is Lynch Syndrome?

Lynch syndrome is a condition that's passed down genetically through families. It dramatically increases a person's risk for developing colorectal, uterine, ovarian, stomach, and other cancers during their lifetime. If one parent carries a gene mutation for Lynch syndrome, there's a 50 percent chance that mutation will be passed on to each child, according to the Mayo Clinic. The risk of Lynch syndrome is the same whether the carrier is the mother or father, or the child is a son or daughter. It doesn't cause any symptoms itself or trigger any other side effects—only the increased risk of cancer.

"It's estimated that one out of every 279 individuals in the general population has Lynch syndrome," says Heather Hampel, licensed genetic counselor at The Ohio State University Comprehensive Cancer Center. "Worse, 95 percent of those who have Lynch syndrome don't know they have it."

How Lynch Syndrome Morphs Into Cancer

The condition is caused by an inherited error (or mutation) in one of four DNA repair genes, says Hampel. As your cells grow and divide, they make copies of their DNA (which contain instructions for every chemical process in your body) and pass them along to the new cells—except that sometimes, "typos" happen during replication.

"The role of the DNA repair system is to correct these errors," explains Cedrek McFadden, M.D., double-board-certified GI surgeon at the University of South Carolina School of Medicine Greenville. But when you have Lynch syndrome, your repair system is faulty and lacks the ability to correct the mistakes. As the errors accumulate, so does the genetic damage within the cells. "When one cell gets too much DNA damage, it will become cancerous," says Hampel.

Knowledge Is Power

"If someone knows they have Lynch syndrome, they can benefit from intensive cancer surveillance and prevention options for their at-risk organs," says Hampel. For example, they can start getting colonoscopies at age 20 to 25, and repeat the process biannually (instead of starting at age 50 and repeating it every 10 years like individuals in the general population). "Women with Lynch syndrome can also consider a risk-reducing hysterectomy and removal of their ovaries to eliminate their risks for both uterine and ovarian cancers," she adds.

Should You Get Tested?

If you haven't had cancer but have a strong family history of Lynch syndrome-associated cancers (which include colorectal, uterine, ovarian, stomach, kidney, brain, and bile duct cancers, according to the American Cancer Society), you may want to consider seeing your local cancer genetic counselor for a risk assessment and discussion of genetic testing, says Hampel. (A simple way to see if you fit the criteria is by using the 3-2-1 rule—three affected family members, two generations, one under age 50, says Dr. McFadden.)

How to Get Tested for Lynch Syndrome

"You can ask your primary care physician for a referral to your local cancer genetic counselor, or you can make an appointment yourself," says Hampel. (To find one near you, use the "Find a Counselor" feature on the National Society of Genetic Counselors website.) Your counselor will then analyze a sample of your blood and look at the genes that can have mutations that cause Lynch syndrome, says Dr. McFadden.

But just because you have Lynch syndrome doesn't mean you're destined to get cancer—it only means that your lifetime risk of developing the disease is higher than the general population. How much higher depends on which DNA repair gene is mutated in your family and the specific steps you take to reduce your risk. Your genetic counselor can explain the specifics of your individual risk based on your test results, according to the Mayo Clinic.

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