Researchers at CeMM Research Center for Molecular Medicine have comprehensively characterized the function and structure of the citrate transporter SLC13A5, elucidating how mutations result in a severe epileptic encephalopathy. Using deep mutational scanning of 38 mutant variants, the team detailed the molecular mechanisms by which impaired citrate uptake disrupts neuronal metabolism, contributing to developmental epileptic encephalopathy. Citrate is essential for energy production and signaling in neurons. This study provides a foundation for further variant analyses and therapeutic development targeting this rare but devastating neurological condition.