Guide to Genetic Testing
There are thousands of genetic tests available in the United States today. You may have wondered what they actually are and which test, if any, is right for you. In this guide, we’ll review the basics.
Have you started to see the seasonal ads and promotions yet for genetic testing? ‘Give your family the gift of personalized genetic insights.’ Did this spark your interest in genetic testing and make you wonder what it’s all about? With the popularity of genetic testing, it’s probably a question you’ve asked yourself, especially if you're new to the concept of genetic testing. What actually is genetic testing, and is genetic testing right for me?
What is genetic testing anyway?
Genetic testing involves analyzing a sample (such as blood, saliva, or cells from a cheek swab) to identify changes in chromosomes or genes. There are thousands of genetic tests available in the United States today. Traditionally, genetic testing was only recommended and ordered by your doctor, but that’s changing. These medical-grade genetic tests are performed through diagnostic laboratories subject to strict regulation to make sure their tests are accurate and that their limitations are clear. Below are a number of medical-grade tests that may be ordered for different reasons:
- Diagnostic testing: used to confirm or rule-out a diagnosis, such as sickle cell disease, Down syndrome, or cystic fibrosis.
- Presymptomatic and predictive testing: for healthy individuals or before someone shows symptoms, such as breast cancer or certain forms of heart disease.
- Pharmacogenetic testing: may help determine what medication and dosage will be most effective and beneficial for you to treat a particular condition or disease.
- Carrier screening: for any individual or couple who is planning to have children and would like to understand risks for genetic conditions in their offspring.
- Prenatal testing: during pregnancy, genetic screening tests can determine if there is a higher chance of certain conditions in the baby. Other tests, known as prenatal diagnostic tests, can determine if the genetic condition is present or not in the baby.
- Newborn screening: newborns are tested for certain genetic and metabolic changes that cause specific conditions, such as phenylketonuria (PKU), and treatment can begin right away.
Medical-grade vs. direct-to-consumer tests
Direct-to-consumer tests, on the other hand, are typically advertised to the general public and can be independently ordered through websites, with samples collected at home, and results received a few weeks later. Most of these tests determine your ancestry or certain traits, although some can detect inherited health risks as well. Although these tests can provide you with some interesting information, such as your ability to taste cilantro or exactly what part of the world your ancestors are from, it’s reasonable to approach the decision on whether to reveal genetic health information with some caution. These tests do not undergo the same regulation as the medical-grade tests described above.
Why would someone pursue genetic testing?
Some people are just curious about their genetics and want to learn as much as they can about their traits and may pursue this testing on their own. Other people pursue genetic testing based on the recommendations from their doctor. They may need to use genetic testing to confirm a diagnosis of symptoms that they have in order to guide treatment or management, or provide information to family members so that they can be aware of their own risks to inherit the condition. Additionally, genetic testing can help individuals and couples understand their own risks for passing on certain genetic conditions to their children.
Should I pursue genetic testing as I plan to build my family?
If you are thinking about getting pregnant, you can find out if you and your partner carry inherited conditions that could affect your future family. Genetic carrier screening can tell you if you carry a genetic change that could increase your risk of having a child with a genetic condition. Many of us are carriers of inherited conditions and simply don’t know it because we show no symptoms. Additionally, about eight in ten individuals who are carriers of a genetic condition have no known family history. It is also important to know as much as possible about your family history, specifically as it relates to birth defects or genetic syndromes, because this information can help determine what genetic test is right for you.
Once a couple finds out that they are at risk to have children with a genetic disorder, they can learn about all of their options. It is best to learn about your genetic risks before you get pregnant, as some reproductive options are only available before pregnancy.
It is best to learn about your genetic risks before you get pregnant, as some reproductive options are only available before pregnancy.
Genetic testing is always optional. Some people choose to undergo genetic carrier testing because they would like to better understand their risks before undergoing a pregnancy. They may consider alternative approaches if they find out there is an increased chance. Other people may decline this testing, as the information may not impact their decision-making and may only cause them undue worry.
What’s the best way to get genetic testing done?
One way to undergo genetic testing is to talk to your doctor at your next office visit. Most genetic testing needs to be ordered by a provider who can manage your results and guide your care. But what if you aren’t going to your doctor as regularly right now or won’t be returning for another year? There are a number of ways to access information on genetic testing and to have genetic testing ordered. Virtual telemedicine visits are now more readily available, and there are companies that employ genetic specialists to guide you in your options. Additionally, since many genetic tests can be performed through a saliva sample or cheek swab, many samples can be conveniently collected while you are at home following your telemedicine consultation.
If this all seems very exciting, but confusing and overwhelming—or you have some questions or just aren’t sure if genetic testing is right for you—you may benefit from seeking a consultation
with a genetic specialist. A genetic counselor is a medical professional who can guide you through the complex information about your testing options and chances of having a child with a genetic condition, which empowers you to make an informed choice and decide what's right for you and your family.
If you have questions about genetic testing, or are interested in speaking with a genetic counselor, you can schedule a session with Genome Medical online, or by calling (877) 688-0992.
Betsy Swope, MS, CGC, is Genome Medical’s reproductive service lead. She is a board-certified genetic counselor with more than 17 years of experience. She has worked at the University of Michigan, the University of North Carolina and Progenity, Inc.