Epilepsy is a widespread neurological disorder characterized by recurrent seizures that affect more than 70 million individuals worldwide. Although more than 30 anti-epileptic drugs (AEDs) are available, treatment response is often unpredictable. There is no “one-size-fits-all” approach applicable to the medical treatment of epilepsy patients and each epileptic patient should be treated uniquely in terms of specific pathogenic mutations. There is a need to better understand the genotype-phenotype-treatment responsiveness correlations to tailor the anti-epileptic medication. In this project, we aim at establishing a proof of concept to generate a patient-specific zebrafish genetic avatar (one patient = one genetic variant = one genetic zebrafish avatar) to test the effect of all available anti-seizure medicines and to identify the best medical treatment for each patient.

We will use a Cre-Lox transgenic approach to introduce a specific LoxP site namely Lox71 within the 5’UTR of the endogenous zebrafish gabra1 gene (an epilepsy-causing gene) that allows stable and irreversible recombination events (with Lox66 site). Using CRISPR/CAS9 knock-in, we will generate stable transgenic zebrafish lines carrying the Lox71 site at the 5’UTR of the zebrafish gabra1 gene. Once this line is established, we will recombine the Lox71 site with a Lox66 site encompassing a cDNA encoding GFP (as a negative control), a WT gabra1 cDNA (as a positive control) or a mutant cDNA encoding the precise GABRA1 variant of a particular epileptic patient. Further, we will perform behavioural studies and a light-induced seizure assay to assess the capacity of each AED to alleviate the seizure phenotype. Finally, using these Cre-Lox “customizable” zebrafish models we can identify which AED is the most suitable for a specific epileptic patient (precision medicine).