Eighty percent of rare diseases are genetic.1 Genetic testing is a tool that can help identify these conditions in individuals and families. It helps empower people to make informed decisions about their health. This blog is a starting point—continue to educate yourself and discuss with a healthcare provider whether genetic testing it is right for you!
Genes and Genetic Diseases
Genes are found in every cell of the body and are made of up of DNA (deoxyribonucleic acid).2 Each gene tells the body how to make a specific protein. Proteins make up the structure of cells, process and transport chemicals, and carry out all bodily functions that we need to live.3
Sometimes, a person has a variant (may also be called a mutation or a change) in a gene that doesn’t allow it to give the right instructions to the body, which can cause disease.
Genetic Testing
Genetic testing looks for and identifies those variants (or changes) in genes, chromosomes (long strands of DNA that contain many genes), or proteins that can cause disease. This medical test can be performed on a sample of blood, hair, skin, and amniotic fluid (the fluid that surrounds a fetus during pregnancy).4
What is a genetics consultation?5, 6
A genetic consultation is an appointment with a geneticist and/or genetic counselor to help you understand your risk for a genetic condition based on your family history.
Geneticists are doctors who specialize in the diagnosis and management of people with genetic conditions. Genetic counselors are healthcare providers who may work with geneticists or may work independently. They can help determine whether genetic testing is right for you, explain what the results of genetic testing may mean for you and your family, and provide support and resources as you make decisions in your healthcare.
Find a genetics professional in your area:
Types of Genetic Testing
There are different types of genetic tests. In some cases, multiple tests may be required to confirm a diagnosis and other family members may also need to be tested.
- Diagnostic Testing checks for specific, known genetic conditions in a person with features of a disorder or who may be at risk of developing signs and symptoms in the future.
- Single Gene Testing looks for changes in only one gene. Usually this is done when your healthcare provider believes you may have a specific condition.7
- Panel Testing Panel Testing categorizes and tests for a number of different disorders that could be causing features in the person being tested. Some examples are testing for seizures, short stature, bone disorders, or muscle weakness. Not all tests look for the same genes, so if you receive a panel test, be sure to ask which genes were tested.7
- Exome Sequencing identifies changes in exons, or the parts of a gene that create proteins, where most disease-causing mutations occur.7 It is typically done if all other tests haven’t determined the underlying cause of disease but may not be able to test all parts of a gene. Negative results don’t mean that a mutation isn’t present.
- Genome Sequencing tests your genome (all the parts of your DNA), not just the genes, since some disease-causing mutations can occur outside of the exons.7
- Carrier Testing checks if a person is a carrier for a genetic disease based on family history or ethnicity. Most carriers do not show any signs or symptoms of the disease. Some couples choose this type of testing before having a baby, because if one or both are carriers, there is risk for the baby to develop the condition.
Unfortunately, no genetic test can identify all known conditions and not all tests are available in every region. Talk to your doctor or a genetic counselor to see what your options are and check out these resources to learn more about genetic testing and finding a diagnosis.
- Centers for Disease Control (CDC) and Prevention
- Global Genes
- NIH Genetic Home Reference
- Undiagnosed Diseases Network
Benefits of Genetic Testing
Genetic testing may help:
- Find a diagnosis for you and other family members
- Inform healthcare decisions and family planning choices
- Increase understanding in the science of the disorder
- Lead to management options that you may have not known were available
- Allow families or individuals with the same genetic condition to connect
- Empower patients to advocate for more research, family support, and treatments
Limitations of Genetic Testing
Genetic testing cannot:
- Tell you everything about a diagnosis, and not all conditions can be diagnosed through genetic testing.
- A positive result can’t tell you how mild or severe the symptoms may be.
- A negative result may not rule out the possibility that you have a disorder because it may not be possible to detect all genetic changes. Your doctor or genetic counselor will be able to explain this.
- An inconclusive result means there isn’t enough available information to determine if your mutation means that you have a condition or not. Again, your doctor or genetic counselor can help explain your situation and whether additional testing would be helpful.
The Genetic Information Nondiscrimination Act of 2008 (GINA) protects you from genetic discrimination by employers and health insurance companies. However, federal law does not protect you against discrimination in the purchase of disability, life, and long-term care insurance.8
Analyzing the Results
The type of genetic testing performed will determine when you will receive your results. Some results take just a few days; others can take months.
Results can affect not only the person being tested, but family members as well. That’s why it’s important to meet with healthcare providers like geneticists and genetic counselors to discuss the interpretation of the results and follow up on medical care and emotional support.
What’s Next?
Cost
Genetic testing costs can range from less than $100 to more than $2,000, depending on the test.9 Cost also increases if more than one test is required, or if multiple family members need testing. While it can be costly, there are some no-cost genetic testing programs designed to help people get diagnosed earlier and more easily. Check them out below.
Family Health History
If you’re considering genetic testing, it may be useful to collect your family health history. Doing so can help your doctors and other healthcare providers give you the support you need. To learn more about what types of information you might need and how to collect it, check out this resource from the American Medical Association.
Genetic testing is a personal decision. If you or a family member have a medical condition or symptoms, discuss with your doctor whether genetic testing is right for you.
References:
- Field MJ, Boat TF, editors. Rare Diseases and Orphan Products: Accelerating Research and Development. Washington (DC): National Academies Press (US); 2010. Profile of Rare Diseases. https://www.ncbi.nlm.nih.gov/books/NBK56184/.
- Genetics Home Reference. What is a gene? https://ghr.nlm.nih.gov/primer/basics/gene. Published July 7, 2020. Accessed July 22, 2020.
- Genetics Home Reference. What are proteins and what do they do? https://ghr.nlm.nih.gov/primer/howgeneswork/protein. Published July 7, 2020. Accessed July 22, 2020.
- Genetics Home Reference. What is genetic testing? https://ghr.nlm.nih.gov/primer/testing/genetictesting. Published June 23, 2020. Accessed June 28, 2020.
- Genes in Life. Geneticists. http://www.genesinlife.org/testing-services/working-healthcare-professionals/geneticists. Accessed August 4, 2020.
- About Genetic Counselors. Who are Genetic Counselors? https://www.aboutgeneticcounselors.org/who-are-genetic-counselors. Accessed July 1, 2020.
- Centers for Disease Control and Prevention. Genetic Testing. https://www.cdc.gov/genomics/gtesting/genetic_testing.htm. Updated March 23, 2020. Accessed July 23, 2020.
- About Genetic Counselors. Frequently Asked Questions + Resources. https://www.aboutgeneticcounselors.org/FAQs-Resources. Accessed July 1, 2020.
- Genetics Home Reference. What is the cost of genetic testing, and how long does it take to get the results? https://ghr.nlm.nih.gov/primer/testing/costresults. Published August 4, 2020. Accessed August 4, 2020.
