Developmental Epileptic Encephalopathy in a Pediatric Patient: Insights from a Novel SULT4A1 Variant and Genetic Challenges.

This article focuses on a case of developmental epileptic encephalopathy (DEE) in a 2.5-year-old girl with refractory seizures, in whom whole-exome sequencing (WES) identified a novel homozygous splice-site variant in the SULT4A1 gene, which encodes a brain-specific sulfotransferase involved in glutamatergic signaling. The patient's clinical presentation, including seizures and developmental delays, alongside similar but variable symptoms in a sibling with the same genetic variant, suggests variable expressivity or age-dependent onset rather than incomplete penetrance. Despite partial improvement with immunotherapy, seizure control remained challenging, underscoring the complexity of managing genetically influenced DEE. The report emphasizes the importance of genetic testing, functional studies, and genetic counseling in diagnosing and treating rare neurodevelopmental disorders linked to SULT4A1 mutations.