Zebrafish Models of PCDH19-related Pediatric Epilepsy
Epilepsy
affects one in 200 children, many with a genetic etiology. Inherited and de
novo heterozygous mutations in the X-linked PCDH19 gene are associated with
“female-limited epilepsy,” characterized by refractory early onset
seizures, intellectual disability, autism, and behavioral problems. To date,
there are no PCDH19-specific treatments or animal models to study this
condition. Zebrafish have emerged as a simple, robust vertebrate model to study
epilepsy and other neurodevelopmental diseases. Our preliminary data indicate
that genome-edited zebrafish models of PCDH19-related epilepsy display
behavioral and electrophysiological abnormalities. The focused goals of this
proposal are to establish clinically relevant pcdh19 zebrafish models and to
screen the effects of available AEDs.
Our
goal is to establish genetic models of PCDH19-related epilepsy in zebrafish to
study the cellular and network abnormalities underlying PCDH19-related
epilepsy.
Using the CRISPR/Cas9 system, we will introduce
patients’ PCDH19 into this model system to evaluate for spontaneous seizures
and proconvulsant-induced seizures that can be detected visually and with
locomotion detection. In addition, we will perform electrophysiological
recording to assess for tendency to seizures and to confirm that a given model
is ‘epileptogenic.’ We then expose these models to anti-seizure medications to
evaluate for reduction in seizures. These studies will set the stage for
high-throughput drug screens of additional compound libraries, thus moving us
toward the goal of “precision medicine” for this and other pediatric
epilepsies.