Psychology & Neuroscience
Treating Epilepsy BY LASYA KAMBHAMPATI
Image from Yale Medicine, 2019
E
pilepsy is one of the most common neurological disorders, affecting over 3.4 million people in the U.S. alone.2 There are over a dozen different types of epilepsy, which makes it hard for doctors and researchers to determine the exact cause of each type.5 Epilepsy’s mysterious origins make the task of finding a cure or effective treatment significantly harder. Dr. Erin Heinzen, an associate professor at the University of North Carolina at Chapel Hill, is on a mission to change the outlook of epilepsy research. While in pharmacy school, Dr. Heinzen recognized the lack of effective treatments for neurological diseases. “Instead of trying to make the old medications that weren’t great work better,” Dr. Heinzen decided to “retrain as a human geneticist to figure out what causes epilepsy better.” In doing so, she would be able to eventually design better medications for epilepsy.1 This realization inspired her to take a step back and join the effort to create better medicines, particularly for epilepsy.1 Specifically, she hopes to identify the genetic cause of neocortical focal epilepsy, a condition characterized by seizures that originate in the neocortex and are restricted to a certain section of the brain. The lack of definition of brain lesions that cause neocortical seizures makes it difficult to identify and target problematic regions for treatment.6 Dr. Heinzen identifies genetic variants associated with neocortical focal epilepsy by sequencing samples
taken from human patients with the disease.1 As a last resort for patients consistently struggling with seizures, doctors perform a procedure in which they remove the part of the brain that is ‘acting up.’ The Heinzen Lab receives some of these samples and analyzes them for genetic anomalies that could represent causal factors of epilepsy. Dr. Erin Heinzen Interestingly, the Heinzen Lab has identified inconsistencies in the genetic mutations found throughout the brain. In order to determine whether these mutations are somatic or inherited, they compared the genetic sequence to the DNA sequence in blood samples from the patient.1Oftentimes, identified mutations proved to be unique to specific parts of the brain and were not found throughout the whole body. These mutations present in a mosaic fashion and are believed to have occurred during development.3,4 The earlier in development the mutation arose, the more widespread the variant would become. The Heinzen Lab hypothesizes that neocortical focal epilepsy might result from these localized mutations. To verify this, the lab seeks first to identify mutations of interest. However, many of the samples that the lab receives have 10-15 somatic variants, making it difficult to determine which
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