Abstract
In Kazakhstan, data on genetic causes of epilepsy have been limited, posing challenges for clinical management. This study conducted whole-genome sequencing (WGS) in 20 pediatric patients with early-onset epilepsy of unknown etiology, enrolled between July and December 2021. The average age at enrollment was 34.5 months, and the mean age at seizure onset was 6 months; 30% of participants were male, and 7 had familial cases. Pathogenic or likely pathogenic variants were identified in 14 (70%) patients, including six novel disease-associated variants in KCNQ2, CASK, WWOX, MT-CO3, GRIN2D, and SLC12A5. Additional implicated genes included SCN1A (in two cases), SLC2A1, ARX, CACNA1B, PCDH19, KCNT1, and CHRNA2. The findings confirm the predominant role of genetic etiology in early-onset epilepsy (70%) and underscore the necessity of next-generation sequencing in diagnostics. Furthermore, the study expands the understanding of genotype–phenotype correlations in genetic epilepsy. Although limitations exist, the results emphasize the broad genetic heterogeneity of pediatric epilepsy in Kazakhstan and point to the need for further research.