Frequently Asked Questions About Epilepsy Genetics Testing
What Is Genetic Testing and Why Is It Useful?
Genetic testing is usually performed on a blood sample, or less frequently, on a saliva sample. The DNA is extracted (taken out) of the cells and analyzed in the genetic testing lab. The genes that are analyzed in the laboratory are the genes specifically ordered by your provider. Most people have a type of genetic test called a panel. Panel tests look at multiple genes related to the same condition. Panel tests vary in the number and type of genes included. Some patients have a test called a microarray. This looks for big pieces of genetic information that are missing or extra. Other patients have a test called Whole Exome Sequencing, which analyzes all of the genes in the body that code for proteins. This test focuses on genes related to the indication for testing, but can also reveal unexpected findings if a family decides to find out this extra information (i.e. a hereditary cancer syndrome or a hereditary cardiovascular disease).
Genetic testing is useful in the diagnosis and management of children with epilepsy. Because there is phenotypic overlap between several genes related to epilepsy, genetic testing is the only way to know the cause for certain. Having a genetic diagnosis allows you and your child’s doctors to have better information about prognosis, understand the chance of someone else in the family having epilepsy, choose a better medication or treatment, avoid other invasive or expensive testing to find the cause, and to connect with other families who have the same or a similar diagnosis.
What Are Genes?
Genes are our body’s instructions for how to make proteins. Proteins are the building blocks of our body. Our genes are stored on structures called chromosomes, which are located in the nucleus of every single cell in our body. Humans have approximately 22,000 genes.
What Is a Mutation?
A mutation is like a mistake in the gene. Think of genes like recipes. If you're baking a cake and follow the recipe exactly, it should turn out as intended. However, if there is a mistake in the recipe, the cake is still able to be made but it will not turn out correctly.
This is similar to how mutations work in our genes. If there is a mistake - or a mutation - in a gene, the protein can be made incorrectly or in some cases, not made at all.
What Do My Child’s Results Mean?
- Negative: This does NOT mean your child’s condition is not genetic. This means no mutation was able to be identified from that particular test. Your child may need more comprehensive genetic testing or a different kind of genetic testing.
- Variant of Uncertain Significance: This means a change was found in a gene, but we do not know the significance of that particular change. Some changes in genes are harmful and impact the function of the gene. Other changes are normal variations and do not impact the function of the gene. When scientists do not have enough information about a particular change, the change is classified as a Variant of Uncertain Significance (sometimes abbreviated as VUS).
- Positive: This means a mutation was identified in a gene that may explain your child’s medical history. In some cases, a positive result may change your child’s medical management, give your family information about the chance other members of your family could have epilepsy including future children, give you information about why your child has epilepsy, and a better understanding of what to expect.
Will My Child’s Insurance Company Pay for This Testing?
In most cases where testing is medically necessary, health insurance companies will cover genetic testing. Prior authorization and pre-determination through your insurance company is important to make sure the testing is covered and to determine your out of pocket cost for testing.
Can My Child’s Genetic Information Be Used Against Them?
In 2008, the United States passed the Genetic Information Nondiscrimination Act (2008). This prohibits health insurance companies and employers from using genetic information or genetic diagnoses against patients. However, this act does not protect against discrimination from life insurance companies, long-term care insurance companies, and disability insurance companies. For more information, please visit ginahelp.org.