DNA Testing 101

By Laurel-Ann Dooley

Ever wonder if you’re at risk for the disease your grandmother had? Curious how you might respond to certain medications? Trying to figure out why dairy leaves you bloated? The answer may be in your DNA.

How DNA Testing Can Help

Genetic testing is currently utilized to identify thousands of conditions, including various hereditary cancers, neurological diseases, metabolic disorders and cardiovascular conditions. In family planning, it is commonly used for carrier screening for conditions such as cystic fibrosis and sickle cell disease.

Today, most people encounter DNA testing in one of two ways:

Through a healthcare provider

Clinical testing is designed to answer specific medical questions, such as confirming a diagnosis, clarifying disease risk or guiding medication choices through pharmacogenomic testing.

Through direct-to-consumer kits

These tests often focus on ancestry, traits and wellness insights such as metabolism, fitness response or food sensitivities. They can be interesting, but they aren’t designed to diagnose or guide treatment.

“Clinical genetic testing is usually performed only when someone has a personal or family history that raises concern for a specific type of genetic condition,” says Jordan Hunter, manager of high-risk programs at Piedmont Atlanta Hospital.  It may be used to confirm a diagnosis in someone with symptoms or to identify elevated risk for conditions such as certain cancers or heart disease, giving patients the opportunity to take proactive steps.

DNA Testing in The Wellness World

As DNA testing has become more accessible, it has also moved into the wellness space, where many reports promise personalized guidance for diet, supplements, fitness and even mental health. Instead of looking for disease risk, these panels analyze common genetic variants and group them into categories such as nutrient metabolism, detoxification pathways, inflammation, hormone balance and medication response.

One of the most evidence-based areas is pharmacogenomics, which looks at how specific genes affect the way the body metabolizes certain medications. In clinical care, this information is already used for a defined number of drugs — including some antidepressants, pain medications and blood thinners — to help physicians choose a medication or adjust dosing based on whether someone is likely to process it too quickly, too slowly or at a typical rate.

Wellness reports also frequently reference methylation, a normal biochemical process your body uses to turn genes on and off and to support functions such as neurotransmitter production, hormone regulation and DNA repair. If a test shows a common variant in a gene involved in this pathway, it is often interpreted as a need for specific forms of B vitamins or other targeted supplements.

This is where confusion can happen. A genetic variant does not mean your body is deficient in a nutrient, and it does not diagnose a condition. Most of these variants are common in the general population and may simply indicate that your body processes something differently. Your current health, diet, sleep, stress level and lab work all play a much bigger role in how those genes are actually expressed.

The Bigger Picture

Because genes are only one piece of the picture, experts caution against treating DNA reports as stand-alone treatment plans.  The most meaningful way to use this information is alongside a qualified healthcare professional who can connect genetic tendencies with your symptoms, medical history and lifestyle to determine whether any changes are truly necessary.

Even genetic testing led by medical experts can have downsides. “Genetic testing can be extremely helpful, but it’s important to understand that it also has potential downsides,” says Trevor Feinstein, MD, director of research at Piedmont Fayette Hospital and chief medical officer of Georgia CORE. Results can create anxiety, be uncertain or lead to unnecessary follow-up testing, and a negative test does not eliminate disease risk. “Testing helps determine predisposition, not whether the disease will occur.”

In the end, genetic testing can be one more way to better understand your health. With the right professional guidance, you can determine whether it belongs in your overall health planning. To find a genetic counselor, ask your doctor or visit findageneticcounselor.com.

5 Questions to Ask Before Pursuing Genetic Testing

1. Does my family history suggest I actually need this test? The types of conditions in your biological family and the age they appeared help determine whether clinical testing is recommended.
2. Will the results change my medical care? Testing is most useful when it impacts your screenings, medications or prevention plan.
3. Should I work with a genetic counselor?
   A specialist can guide test selection and turn complex results into clear next steps.
4. Am I looking for clinical answers or wellness insights? Medical genetic tests and direct-to-consumer reports are not designed for the same purpose.
5. Has anyone in my family already been tested? A relative’s results may provide the information your provider needs without repeating testing.

Piedmont Atlanta Hospital, piedmont.org
Georgia CORE, georgiacancerinfo.org