Genomic Profiling of Adults with Pharmacoresistant Genetic Generalized Epilepsy

Background/Objectives: Genetic generalized epilepsies (GGE) often remit in childhood, yet a subset of adults remain pharmacoresistant with substantial morbidity. The genetic basis of adult pharmacoresistant GGE is poorly defined. This descriptive study used whole-genome sequencing (WGS) to identify recurrent coding variants and pathways associated with pharmacoresistant adult GGE. Methods: WGS was performed in ten racially diverse adults (mean age 37.2 years; range 20-52) with electroencephalographically confirmed, pharmacoresistant GGE (mean onset 13.7 years). Analysis prioritized variants present in at least 80% of participants and which were either (i) missense variants predicted deleterious with ANNOVAR or (ii) loss-of-function variants predicted high-impact from snpEff. Pathway enrichment and overlap with a commercial clinical epilepsy gene panel were assessed. Results: Filtering identified 133 unique, deleterious coding variants across 69 genes shared by at least eight participants. Four genes (APOL4, KMT2C, SON, VDR) overlapped a clinical epilepsy panel, supporting the capacity of WGS to recover clinically relevant loci. Prioritized loci implicated gastrointestinal and metabolic regulators (e.g., MUC6, PNLIPRP2), chemosensory receptors (OR10D3, OR8U1, TAS2R19), neuroimmune mediators (LILRA2, SIGLEC12, OAS2), and ion transporters (KCNJ12, P2RX5, RHBG), consistent with multifactorial mechanisms of pharmacoresistance. Conclusions: This exploratory WGS study focused exclusively on adults with pharmacoresistant GGE, revealing shared high-impact variants and convergent pathways spanning absorption/metabolism, vitamin D signaling, immunity, and ion transport. Findings broaden the genetic landscape of pharmacoresistant GGE while motivating validation in larger, multiethnic cohorts.