What is genomic screening?
From newborn screening to cholesterol screening to mammograms and colonoscopies, most of us have been offered, or undergone, some type of health or medical screening during our lives. So, what exactly is genomic screening, and what is the difference between genetic testing and genomic screening?
Screening tests find diseases or possible health conditions in people without symptoms. Their goal is to find people early so that lifestyle changes and/or earlier surveillance can be started to reduce the disease risk and/or treat it as early as possible. Screening tests are different from diagnostic tests, as they are not used to make an actual diagnosis in most cases, but instead are meant to find a specific subset of a population of people who should have additional testing to see if they do, or do not, actually have the condition in question.
How might I access genomic screening?
Many institutions are trying to make DNA screening a part of individuals’ routine healthcare. Multiple healthcare systems across the country have launched clinical and/or research-based genomic screening programs, or have announced that they plan to launch new programs for their patients, ranging in age from newborns to adults. If you are a patient at one of these centers, you may be offered participation in genomic screening.
Additionally, the National Institutes of Health’s All of Us Research Program, plans to enroll 1 million people and return clinically relevant results. Your employer and/or your insurance plan may also offer you genomic screening as a covered benefit. Some individuals also seek out genomic screening on their own as they may have a family and/or personal medical history that concerns them, or they may want to know more about their health overall. Typically, consumers can initiate this test in a couple of ways:
- They can indicate to a testing company that they would like a genomic screening test and then a healthcare provider orders that test for them.
- They can order the test themselves via a direct-to-consumer genetic testing company.
What is involved in the genomic screening process?
The genomic screening process will differ depending on the setting and whether you access this via your healthcare provider, as part of a research study or from a genetic testing company directly. Typically, you will be asked to go through an informed consent process before you submit a biological sample, usually blood or saliva, for genomic screening. The informed consent process should ensure that you understand the potential benefits, risks and limitations of genomic screening. You should also understand the types of results you may receive and who will or will not have access to them before you provide a sample.
Some questions you may want to ask before screening include:
- What types of conditions does this genomic screening include?
- What is involved in follow-up testing?
- What is the cost?
- Who will have access to my results?
- Who will provide my results to me and explain what they mean?
- What could this mean for my family?
- Is this the right type of genetic testing for me, based on my medical and family health histories?
- Do you offer genetic counseling?
I have a result in hand, now what?
Perhaps you’ve already undergone genomic screening, and have a result in hand, and now you need to figure out what to do with it. Or, perhaps you’ve already provided informed consent to participate in a genomic screening program, and you’re awaiting your results. Let’s walk through having a positive result, and then a negative result.
I have a positive result
This means that the genomic screening likely identified a genetic variant that may increase your risk of developing a condition such as cancer, heart disease, or another condition included in the genomic screening you underwent. It will be important for you to ask the genomic screening program, your healthcare provider, or a genetic counselor whether you need a follow-up test called, “clinical confirmatory genetic testing.”
Clinical confirmatory genetic testing is typically done on a new sample of your DNA to make sure the variant identified by genomic screening is really there. This is very important to do before you make decisions regarding your healthcare with your healthcare provider. You may also want to seek evaluation by a specialist with expertise in the condition you were identified to have increased risk for, such as a cardiologist, if the variant identified gives you an increased risk for heart disease, such as an arrhythmia or an aneurysm. The genetic variant identified in you also has health implications for your at-risk relatives. So, it’s very important that you tell your close relatives (parents, siblings, children) and other relatives about your result so that they can have genetic testing to determine whether they also have the risk identified in you.
I have a negative result
This means that the genomic screening did not identify a variant associated with disease risk in you. However, it is very important to understand that not all genomic screening tests are the same. If you are concerned about your personal and/or family medical histories, you may need an actual clinical genetic test to tell you whether you have a genetic condition or whether you have a genetic variant that could increase your risk for certain conditions, such as cancer. Most genomic screening tests are incomplete, as they only include a predetermined list of genes or a predetermined number of genetic variants.
The bottom line is that if you have a negative genomic screening test result but still have concerns about your genetic risks, it’s best to talk to your healthcare provider and/or a genetic counselor to determine if additional clinical-grade genetic testing is a good next step for you.
How can genetic counselors help?
Genetic counseling performed by board certified and/or licensed genetic counselors is oftentimes included as part of the genomic screening process. In fact, some programs require genetic counseling to access positive genomic screening results.
Genetic counselors will help you put your result into the context of your personal medical and family histories and will explain what the result means for your future health, what it means for the health of your family, and will also provide a personalized care plan in partnership with your primary care and specialty care providers.
Genetic counselors will also help you adjust to this new information, as it may take you by surprise, especially if you test positive for a condition that does not appear to run in your family at all. Genetic counselors are also there to help you throughout your healthcare journey as you utilize the information gleaned from genomic screening and determine whether clinical genetic testing may also be right for you.
Find a genetic counselor in your area or via telehealth at findageneticcounselor.org.
If you’re curious to learn whether you may be a good fit for genetic counseling, visit our free patient referral tool.
Amy Curry Sturm, MS, CGC is Past President of NSGC’s Board of Directors, NSGC’s cardiovascular genetics expert and Director of Population Health Genomics at 23andMe.
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