DHDDS-related epilepsy with hippocampal atrophy: a case report

Developmental delay and seizures with or without movement abnormalities (DEDSM) is a neurodevelopmental phenotype associated with monoallelic mutations in the DHDDS gene. We report a novel case of DEDSM linked to a DHDDS variant (c.614G > A, p.Arg205Gln) in a 45-year-old Brazilian patient presenting with refractory epilepsy, ataxia, dystonia, parkinsonism, and global developmental delay. This is the first case to associate a DHDDS variant with hippocampal atrophy on neuroimaging. After adjustments in anticonvulsant therapy, seizure control was achieved, and the patient—who was previously unable to walk due to frequent falls attributed to myoclonic jerks—showed significant improvement in gait and mobility.