BACKGROUND AND OBJECTIVES: genes are recognized as major causes, the full genetic spectrum remains uncertain. We aimed to delineate the electroclinical characteristics, genetic etiologies, and long-term outcomes in a large MRI-negative EIDEE-BS cohort. METHODS: , "other pathogenic variants," and "without a genetic diagnosis." EEG traces were reviewed independently, and outcomes were assessed through long-term follow-up. RESULTS: ). Most variants were de novo heterozygous; however, recessive and X-linked inheritance patterns were also observed. Mortality was high (25%), primarily from status epilepticus and complications of severe disability. Most patients (72.5%) had persistent seizures at follow-up (a mean of 6.5 years), as well as profound intellectual disabilities, irrespective of genotype. DISCUSSION: were the most commonly affected genes. Early EEG features, particularly BS timing and morphology, can help anticipate the underlying genotype and guide precision therapy, including the early use of sodium channel blockers in selected cases. These findings support recent ILAE reclassification efforts and underscore the importance of comprehensive genomic testing for improved diagnosis and counseling.
Riccardi et al. (2026) studied this question.