If you’re anything like us, you’ve probably been eyeing the fancy mail-in genetic tests that are all over the internet these days, wondering what they could possibly reveal about the secrets of your DNA.
Although many offer entertaining insights – curious if you’re genetically predisposed to sport, a unibrow, or sneeze when you look at the sun? – the real potential of such testing is to reveal your likelihood of developing serious health conditions.
In an ideal world, knowing what’s lurking in your DNA would motivate you to get more mammograms or other screening exams. Or you’d get serious about taking omega-3 fatty acids or commit to daily exercise strategies that researchers believe will delay the onset of Alzheimer’s. Yet, as the applications for genetic testing expand, experts say we have the opportunity to learn more about our risk for certain diseases than we ever imagined possible.
“People are really interested in genetic testing right now. More of my patients are asking about it, and I’ve overhead parents chatting about it at my son’s little league games,” explains Dr Bradley Patay, an internal medicine specialist at Scripps Clinic Torrey Pines in La Jolla, California. “This interest gives us a unique opportunity to really educate the public about the potential of genomics. Plus, the price has been coming down, so there’s some momentum to get patients engaged.” (Although the new consumer tests analyse your DNA for several conditions, your doctor might need to order a specific test, which could be covered by insurance.)
In the leap to learn more about ourselves, however, it’s important to know what genetics can and can’t tell you. Just because you have a genetic predisposition for a disease doesn’t mean you will get it, says Mary Freivogel, president of the National Society of Genetic Counselors. “Your environment, family history, lifestyle habits, and even pure chance also play a role,” she says.
Here, we share some genetic breakthroughs that should be on everyone’s radar:
We know that healthy lifestyle habits are linked to a lower risk of heart disease, which is the leading cause of death in women, according to the Centers for Disease Control. (You’ve heard them before: No smoking, maintaining a healthy BMI, exercising regularly, eating a diet low in red meat and saturated fat.)
Yet a landmark 2016 study of more than 55 000 participants that was published in The New England Journal of Medicine discovered just how critical those habits were for people who had a genetic risk for heart disease. The participants underwent DNA testing that looked at 50 different markers for coronary artery disease. For those who tested in the highest-risk group, adhering to a favourable lifestyle brought down their risk by 50%
“This is significant research that explains the genetic underpinnings of heart disease and lets patients take actions to reduce their risk,” explains Dr Patay. “In addition to changing your lifestyle, if you knew you were in the high-risk group, you might choose to take a statin medication earlier than you normally might,” says Dr Patay. “That’s not a conversation doctors are routinely having with patients, but that’s going to change as we learn more.”
This might not be your idea of Sunday dinner conversation, but asking who in your family has had what are called adenomatous polyps can help you know if you’re at risk for colorectal cancer.
Such polyps might develop in your colon during your teen years, but become malignant as you get closer to 40. As many as one in five people who get the disease are related to someone who’s had it, according to the American Cancer Society.
“People usually start getting screened for colorectal cancer at age 50, but if you have a family history of colon cancer or polyps, you might need to start earlier and talk to a genetic counsellor,” says Freivogel.
As the popularity of gluten-free products surged over the past decade, the world became a lot more aware of the trials and tribulations of people who suffer from coeliac disease. Unlike people with intolerances who deal with temporary digestive issues after eating gluten, coeliac patients who ingest the wheat protein experience serious harm to their small intestine.
According to the Celiac Disease Foundation, people with a first-degree relative with the disease (meaning a parent, child, or sibling) have a one in 10 risk of getting this themselves, since there are genes associated with coeliac disease. Although having one or more gene doesn’t necessarily mean you’ll develop the disease, you shouldn’t delay getting evaluated by a doctor if you also develop the classic coeliac symptoms of abdominal pain or weight loss.
Sadly, people often only learn they have this deadly condition when a loved one has a heart attack at a young age. People with the genetic disorder called familial hypercholesterolemia (FH) have dangerously high levels of LDL, or “bad cholesterol”, from birth and are 20 times more at risk for early heart disease, including heart attacks and stroke, according to the FH Foundation. Genetic testing combined with a simple blood cholesterol test can lead to diagnosis and treatment with statins.
“FH is the most common genetic cause of early heart disease, but with early treatment an individual’s risk can be reduced by 80%,” says Dr Daniel Rader, professor at the University of Pennsylvania’s Perelman School of Medicine. “Unfortunately FH is highly undiagnosed, with 90% of people unaware they have the condition.”
Researchers still have so much to learn about the genetic roots of mental conditions. Still, looking at your family history can provide clues to your blues. “Just because someone in your family has depression doesn’t mean you will, but it’s more likely if two or more people on the same side of your family are affected,” says Freivogel.
Being mindful of your family’s mental-health history might prompt you to seek treatment if you’re going through a rough patch, and some genetic tests can help determine which medications you’ll respond best to, according to Mayo Clinic.
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