Genetic Testing versus Genetic Counseling: What’s the Difference?

This content was written by Alora Terry, LGC, at Thompson Cancer Survival Center

In the past decade, the information available about genetic testing has greatly increased. It has become more readily available to people everywhere through commercial companies like AncestryDNA and 23andMe. There has also been an increase in primary care providers ordering clinical genetic testing for their patients for a wide variety of medical reasons. While genetic testing has experienced this time of rapid growth, it has been matched by a field of professionals, genetic counselors.

Genetic counselors are specialized healthcare providers responsible for providing the service of genetic counseling. Depending on where or why a person is pursuing genetic testing they may find themselves with a referral to undergo genetic counseling. This makes many people question: What exactly is the difference between genetic testing and genetic counseling, and is it necessary that the two accompany each other?

Genetic Testing

To begin to answer this question it’s important to first define genetic testing. The Centers for Disease Control and Prevention (CDC) states that “genetic testing looks for changes, sometimes called mutations or variants, in your DNA.” In more simple terms, genetic testing is a tool that looks at your genetic makeup, the hereditary information passed to you from your mom and dad, for things that are unique or different than what may typically be expected.

The information gained from genetic testing depends on the type of changes the test is created to evaluate. A genetic test may be able to help a person learn more about their ancestry, to aid in making a medical diagnosis, or it may even help to determine health issues for which a person is at an increased risk.

When people are considering genetic testing, it is important to understand that there are different levels of tests and not all tests are of a medical or clinical grade. Clinical genetic tests are performed through labs that meet standards of quality mandated by the government. This type of testing is used in the medical setting because the results are trusted to have a high level of accuracy and validity, therefore making them useful for medical management.

Testing in the cancer setting  

Hereditary cancer genetic testing is when a person, with or without a personal history of cancer, completes testing to determine if they carry an inherited genetic change that is putting them at an increased risk of developing cancer. The test is typically carried out on either a blood or saliva sample, and results are back in two to six weeks.

So, imagine this scenario. Your mother had a history of breast cancer diagnosed at the age of 40, but she never completed genetic testing to your knowledge. Being concerned about your personal risk you elect to pursue genetic testing to see if you carry a hereditary risk for breast cancer. You get your blood drawn and three weeks later you receive a phone call with the result. It’s reported that you have a genetic change in a gene that likely caused your mother’s history of cancer.

Okay, well what now? What does this actually mean for your health, and what should you do about it?  This is where genetic testing ends. You’ve used the tool and gotten information, but alone, that is all that genetic testing offers. It can be difficult to interpret these results and to understand what options you have to react to the information or if you need to react at all.

Genetic Counseling

While genetic testing is a tool to gain information, genetic counseling is a process that helps interpret the information and place it in a personal context. The process varies slightly depending on the setting of genetic counseling or even the medical professional providing the counseling. However, no matter the slight differences the ultimate goal of all genetic counseling is to help people better understand their health risk as related to hereditary factors and guide educated decisions about what is best for an individual’s healthcare.

Genetic counseling often begins with an initial session that lasts anywhere from 45 minutes to an hour and a half. Most cancer-focused genetic counseling sessions have similar flows as follows:

1. Review patient’s personal health history
2. Review patient’s family history of cancer
3. Discuss cancer and the role genetics play in it
4. Explore genetic testing including limitations, benefits, insurance/legal implications, and possible results
5. Talk through cost, insurance coverage, and logistics
6. Discuss different testing options available
7. Elect to proceed with testing/select appropriate testing option
8. Outline a plan for moving forward

No testing now what?

Not all genetic counseling appointments will end with a person electing to proceed with genetic testing. In reality, about 20% of patients decide not to move forward with testing following an appointment. There are many reasons, such as learning testing wouldn’t be recommended or concerns regarding limitations for future insurance protections. For those that don’t do testing the process is not over.

Every patient will complete the genetic counseling process with an individualized cancer risk assessment and recommendations for cancer screening or prevention based on their personal and family history. This means that even for people that don’t pursue testing they are likely to find themselves with new recommendations for their medical management or perhaps even a sense of relief or new confidence with a better understanding of their own cancer risks.

Tested, now what’s next?

All genetic clinics will handle the next steps a little differently, but there are some things that are rather universal. A patient will have a results disclosure, this may be over the phone, through video chat or even in person. This is where genetic counseling goes leaps beyond just testing because not only will you get the knowledge of a result you will also get actionable steps based on that result, giving a type of power in cancer prevention or early detection. Most often this will involve a discussion of results, what those results mean for the patient and their family members, a national medical society guided recommendations, review of available support systems, networks, or resources, and even help with follow-up testing for relatives or appropriate referrals to new providers.

Conclusion

To summarize, genetic testing is a tool and genetic counseling is a service. They do not always occur together or simultaneously. Genetic counseling helps ensure a person is fully informed of the pros and cons of genetic testing before moving forward with the test, as well as providing personalized actionable medical recommendations. This relationship creates a lasting resource that you may reach back out to over the years for updated medical management recommendations, new research-guided genetics information, or with questions or concerns that arise with a new family or personal history. 

Genetic testing offers knowledge on cancer risks that genetic counseling turns into power for prevention and early detection, helping lead to better treatment outcomes.

References

https://www.cdc.gov/genomics/gtesting/genetic_testing.htm

https://www.nsgc.org/About/About-Genetic-Counselors

How can consumers be sure a genetic test is valid and useful?  https://medlineplus.gov/genetics/understanding/testing/validtest/