Hear ye. Good news about genetic testing for epilepsy this month. A new study out of Stanford University addresses the powerful impact genetic testing can have on treating people with epilepsy of unknown causes. Led by neurologist Dr. Yi Li, the Stanford investigators conducted genetic testing on 286 adults and found pathogenic genetic variants in over 40% of them. In September I blogged about an Australian study that used cutting edge rapid genome sequencing to test babies’ DNA and identify changes that can cause epilepsy. Thanks to studies like this one, genetic testing has become standard practice for children with early-onset epilepsy. But it’s not yet common practice among adults with the condition. Dr. Li’s Stanford study will hopefully change this soon.
Over the past 20 years, technological advances have enabled researchers to identify dozens of epilepsy-related genes. When these are detected in patients, doctors can develop more effective and precise treatment plans. For example, presence of certain genes indicates that specific types of anti-seizure medications, or ASM’s will be the most effective. There is also evidence that some medications don’t work well and may even cause adverse side effects in patients with particular types of genetic epilepsy.
The Stanford study found that a genetic epilepsy diagnosis led to treatment plan alterations in 20% of participants, but patients often wait more than a decade to get it. Dr. Li concluded that genetic testing results have the potential to end the long and exhausting “diagnostic odyssey” patients are forced to embark upon when attempting to control intractable seizures. As a person with epilepsy who tried 14 anti-seizure meds that ultimately failed to control my seizures until I had two brain surgeries, Dr. Li’s odyssey metaphor rings true. My decades-long seizure-control crusade was so onerous and terrifying that I documented all the difficult details into my memoir, Seizing Control.
Had genetic testing been around when I was younger, perhaps my neurologist may have uncovered details that would have let me bypass some of those unsuccessful medication regimens. I’ll never know whether that’s the case. But going forward, hopefully doctors treating patients with refractory seizures will regularly incorporate genetic testing into their toolboxes. The Stanford study increases the chances of this outcome, but as with so many medical procedures, money is a consideration. Although genetic testing is becoming increasingly accessible, insurance companies don’t always cover the cost. The Standford study offers evidence that the diagnostic certainty genetic testing provides improves patient outcomes, and—perhaps more importantly to insurance companies—ultimately saves money, as patients can avoid costly invasive tests and treatments.
The most common genetic tests involve blood or saliva analyses, which are far cheaper and less invasive or intense than many common neurological assessments such as MRI’s, CT scans, and PET scans. Both the International League Against Epilepsy and the National Society of Genetic Counselors recommend genetic testing in adult epilepsy patients. Every insurance plan has its own rules regarding genetic testing coverage. Most plans require pre-approval or prior authorization, and some insurance companies require genetic counseling before they will cover a genetic test. I’ve been seizure-free eight years, but if I still had refractory seizures, I would ask my neurologist to refer me for genetic testing, and work with my insurance company to make sure the procedure was covered. Based on the Stanford study, this would be a good upfront investment that saves time and hassle and can ultimately cut costs for insurance companies when patients’ seizures are better controlled.