As technologists often we are the first healthcare professional that the patient meets on their epilepsy treatment journey.
The EEG combined with the New Patient Visit opens up the door to seizure management and all of the things that follow in their comprehensive evaluation.
For many of our patients Genetic Testing plays a key role. Ever wonder what that looks like for our patient’s and their families? The hopes of this post is to introduce you to genetic testing and how it can benefit and/or guide their treatment.
Epilepsy is one of the most common and diverse neurological conditions.
It's not a single disease but a symptom that is caused by a variety of different diseases; a lot of which, are genetic. With genetic testing, physicians now have that detail in the diagnosis that can often lead to improvements in patient treatment and management.
Genetic testing in patients with epilepsy can inform treatment and lead to better outcomes in many cases.
There are several different types of tests:
Individual or Group genes and Chromosome testing
Because there is no single test that can diagnose all genetic epilepsies, multiple tests may be recommended.
Some common examples of tests for epilepsy include:
Epilepsy Gene Panel
This test involves the analysis of the most common genes associated with epilepsy.
Chromosome Microarray
This genetic test involves analysis of a person’s chromosomes (structures that contain DNA).
It checks to make sure there are no imbalances that could cause epilepsy. Imbalances include extra or missing pieces of chromosomes. Imbalances can also include extra or missing entire chromosomes (also known at copy number variants, CNV’s). This test can be abnormal in approximately 10% of patient’s with epilepsy and more likely in children with developmental delays.
Whole Exome Sequencing
This complex genetic test involves analysis of the entire DNA code to look for changes in genes associated with epilepsy.
It is similar to the epilepsy gene panel, but looks at a much larger number of genes, including rare and newly discovered genes.
Because this test analyzes the entire individual exome there is a possibility of learning about secondary findings unrelated to epilepsy. Because of the risk of discovering other conditions that would otherwise be unknown it is recommended that patient’s are given the opportunity to opt-out of receiving the secondary findings.
Targeted Testing
If there is already a known genetic cause of epilepsy in a person, other family members may have targeted testing to help clarify their risk.
Most genetic tests utilize a blood sample; however, in some cases a saliva sample or cheek swab could be used.
Which epilepsies are most likely to have a positive result from genetic testing?
Primarily Refractory Epilepsy (or epilepsy that is difficult to treat) - these patients also have other Neurological symptoms like developmental delays, autism or other neurological disorders. Typically there also is a strong family history of seizures. However, genetic testing can be beneficial for any patient that has epilepsy and no know cause.
One especially interesting comment that I came across while researching this topic was that genetic testing can have implications regarding future eligibility for life insurance and/or disability insurance. Of course, reproductive decisions and other medical decisions can also be involved so connecting these patient’s and their families with a genetic counselor is often recommended.
For more information please reference the resources listed below and look for additional advancements in this ever evolving and dynamic area.
Roya Tompkins, MS, REEG/EP T, RPSGT
Resources:
The Epilepsy Foundation
American Academy of Pediatrics (AAP.org)