With Thanksgiving behind us and the holidays ahead of us, family is certainly on the mind. For many of us, reunions with family make us reflect on where we came from (our ancestry) as well as the traits and health conditions that we may have inherited. Genetic testing companies are also aware of this and have gone full force in marketing their services and promoting post-Thanksgiving deals. As a genetic counselor, I am super excited that access to testing and getting information about genetic health has increased. However, us genetic counselors all over the world reallllly want you to be informed before sending your DNA in!
If you've purchased or are thinking of purchasing a DNA test either for yourself or for a family member, here are a few things to keep in mind:
If you know of a family member who has a genetic condition and/or has had a variant found by genetic testing, stop right now and refrain from clicking the "add to cart" button. Super important to know more details about the individual that has the condition to ensure that you are selecting the right genetic test.
Next Step- CONTACT A GENETIC COUNSELOR!
If you are interested in taking one of these tests to learn more about your ancestors and where your family came from , it's important to select a test that has a large database of ethnic backgrounds.
This is especially important if you are non-Caucasian. The reality is folks, that most genetic testing and research has been done on the Caucasian population, so we know a little less about the genetics of other ethnicities.
Most of the companies offering these tests, should have information on their websites about which ethnic groups they cover. If ancestry testing is your primary purpose for doing testing, choose one that covers the greatest number of ethnic regions.
Some of the companies offering ancestry testing also offer a service where they try to match relatives based on DNA from others who have submitted samples to the same company. This has been super helpful for people who are seeking out relatives, or for those individuals that are adopted and want to learn more about their biological relatives. Some things to consider about this:
Some individuals have received unexpected information as a result of this matching service. For example, you may receive information that tells you that you are related to people you did not know. There are cases of people finding out that they are adopted, or were conceived via a donor. Most of the time, this doesn't happen, but it can, so just be aware!
You can choose to opt out of this "matching" service if you like.
Genetic Health Information
Some of these tests look for ancestry + genetic health information. It's important to understand the difference between screening tests and diagnostic tests. As well as susceptibility genes or markers vs. genetic mutations/variants. What does all this jargon mean in real people talk?! Here's the breakdown.
Susceptibility markers may increase your chance of getting a genetic condition- but it doesn't mean you will definitely get it. In fact, there may even be people who are affected with the genetic condition but don't have that very same marker. I like using real examples to illustrate what I'm yapping about- so here's one that will highlight this concept. So let's take APOE4 testing (risk factor for late onset Alzheimer's disease) for example. This variant testing doesn't tell us a "yes" or "no" answer about whether or not you may get Alzheimer's, but rather informs us if there is a greater likelihood of developing Alzheimer's. Having the APOE4 variant increases the risk for late onset Alzheimer's- but not always. Many people with APOE4 do not develop Alzheimer's disease. And, if we look at people that do have a diagnosis of late-onset Alzheimer's disease, 30-50% are negative for APOE4.
Bottom line: susceptibility genes aren't the be all and end all; they can be useful in informing if you may have an increased risk for something, but important to realize that there are many other factors that play a part.
So then, what are genetic mutations/variants? These are actual changes in the genes that are known to cause disease. Some of these tests look for genetic traits to see if you are a carrier of a genetic condition such as cystic fibrosis or sickle cell anemia.
If you are a carrier of a genetic condition most often you do not exhibit any symptoms of the condition. Rather, this information helps you understand the risk for your offspring to have the condition.
For most of these conditions, if both you and your reproductive partner are carriers for the same condition, then there is a 25% chance for a child to be affected with the condition.
So we've reviewed that some of these tests look for carrier status which most often will not impact your personal health but will give you information regarding potential risk for offspring. But what about the tests that tell you about your own genetic risk for disease?Some of these tests will also look for changes in your genes that can lead to an increased risk for genetic conditions, such as breast cancer. Key things to remember here are:
Often, they aren't looking at ALL the genes responsible for the condition, just a subset. Also, keep in mind that sitting here in November 2018, we may not even know all the variants that cause some of these conditions.
If you have a family history of one of these conditions, like cancer, and screen negative on these tests (ie, are not found to have a mutation), then you're not really off the hook. What do I mean by this?! Well, until we know the specific genetic cause of what's causing the cancer/condition in your family we can't really tell you if the negative genetic test puts you at a decreased risk. If you are in this category- please seek consult from a genetic counselor who can guide you through the testing process.
If you don't have a family history of any of the tested conditions and are not found to have any mutations, then great; you're likely at a decreased risk - but remember, many of these tests are not looking at majority of the genes known to cause these conditions.
And what if the test comes back and says for example you do have a variant in one of the genes responsible for cancer? Well, it's most likely accurate and does mean that there is a significant increased risk of getting cancer. However, there are definite next steps that need to be taken such as consulting with your doctor.
Make sure you read the fine print. Many of these direct to consumer testing companies indicate that the information given is not intended to be used for health purposes. Why do they say this? Well, it because the testing and analysis process hasn't gone through the same safeguards as say a clinical testing lab needs to go through. So what happens if testing from one of the direct to consumer testing labs indicates that you have a genetic variant? You will likely need to have that test confirmed by a diagnostic test in clinical laboratory that has the safeguards.
Each lab will have different policies on how they safeguard your private genetic information and who they may or may not share your information with. Again, read the fine print so you are in the know.
Sometimes the labs may ask for your consent to use your genetic information for research. Again, this is something that they will directly ask your consent for, so you will likely know if this is the case.
Final Thoughts and Take Home Message!
Direct to consumer genetic testing is a great way to find out a little more information about your genetic background. It can give you some insight into your ancestry, inform you of some genetic traits and potential meaningful health conditions. However, it's important to understand the limitations and to know that it is just ONE piece of the puzzle. Similar to how you would go seek consultation from your doctor if you experienced a troubling symptom (vs. going straight to scheduling a surgery); results from genetic testing can prompt you to take further action to get more info.
So here are the questions that I want you to ask yourself before your DNA is analyzed!
What is driving me to do genetic testing? What answers do I hope to gain?
Am I selecting the right test based on the information that I want to gain?
Do I want to know all this information? How will I handle information that may change the outlook of my future health? This is not an easy one to answer- and there is no right or wrong answer here, just understanding what's right for you. For some people, they want all the info they can get because they feel that having this information keeps them in control and they may alter their behavior, environment, or seek additional medical expertise. Others, feel that knowing this information will cause too much anxiety and prefer to deal with issues as they present.
If you are struggling to find answers to these questions, seek out help. There's a whole profession geared towards helping you parse out these very issues. (If you got this far in reading my post, you've probably already figured out that it's called genetic counseling!) We're like the guidance counselor in high school who puts all the pieces together to help you figure out college stuff- except with your DNA and family history.
By now, the turkey and apple pie leftovers are probably gone and your eyes are probably fatigued from seeking out post-Thanksgiving online deals (or reading this post). My parting words to you are to be informed and empowered to select the best test (if any) as you head into 2019. And, if you were kind enough to gift one of these tests to a friend or family member, do them a favor and pass along this post so that they too can be in the know!
Need more info or want to chat? Send me a message, or contact me via email: firstname.lastname@example.org