House Call: Genetic testing sometimes leads to more questions than it answers

In the past decade, genetic testing has become more available and affordable as technology improves. So what can these tests tell you? What can’t they tell you? And, importantly, what should you consider before you do them?

There are two kinds of genetic testing: clinical-grade genetic testing, which most often requires an order from a physician or genetic counselor, and direct-to-consumer tests that anyone can buy. It’s important to note that the information generated from these two types of testing will be very different.

Clinical-grade testing can look at one gene, a group of genes or the whole genome depending on personal and/or family history. It doesn’t provide information about ancestry. The intent is to provide reliable information about disease risk for specific genes.

One such test is genome sequencing, which looks at every gene on every strand of your 23 pairs of chromosomes and reports on which variants you have of each gene. Another test is a gene panel, which looks at a set of genes and reports on which variants you have of the selected genes.

The information provided by clinical-grade genome sequencing is far more comprehensive than panel gene testing, but it can be overwhelming and difficult to interpret. That’s one of the reasons why your health care provider is important and helpful in this process.

If you are considering a clinical-grade test to determine your risk for a certain disease, it’s best to discuss it with your provider and/or a genetics counselor. Clinical-grade testing is often covered by insurance if certain criteria are met.

DTC testing is a broad test looking at certain genetic landmarks in the genome and provides information about traits, ancestry and health data. Many DTC companies also offer to sequence your data or provide a report of your genetic information. While it can give health information, most DTC companies do not report out reliable health data since there are false positives with DTC testing.

Any disease-specific risks reported must be confirmed with clinical-grade testing in consult with your provider or a genetics counselor. DTC testing is not covered by insurance since the health information provided is generally not medically reliable or actionable. Before opting to do any genetic testing, ask yourself how you might react to the information that you might find yourself needing to manage.

DTC genetic testing can be a fun way to learn more about your ancestral roots, but it also can reveal surprises about your family that you didn’t know, which could be negative or positive. You and your family should be prepared for the information you might receive about your family’s biological history.

There also are negative and positive aspects to clinical-grade genetic testing that you should consider. What if your increased risk is for something for which there are no treatments? Do you want to know about that?

There are genetic pathogenic variants that guarantee illness (the genetic defect for Huntington’s disease is an example). Other variants in genes can determine how high your risk might be to develop a condition. In a situation where a parent has such a disease, you might want to know if you carry the gene so that you can decide whether having children is the right thing for you.

On the positive side, if breast cancer runs in your family, knowing that you have a gene that increases your risk might prompt you to be more vigilant about breast self-exams and annual mammograms. If you do know about an increased disease risk, there are lifestyle choices you can make (lose weight, stop smoking) that could make a difference.

Whatever you decide, it’s always best to consult with your provider about issues and testing related to your health. We can help you navigate the process, interpret the results and develop a plan for your continued health.