Clinical Features of Uridine- Responsive Developmental Epileptic Encephalopathy 50 Caused By Cad Gene Variations

Objective: To analyze the clinical features of children with uridine responsive developmental epileptic encephalopathy 50 (DEE50) caused by CAD gene variations. Methods: A retrospective study was conducted on patients diagnosed with DEE50. The epileptic seizures, anemia, peripheral blood smear, cranial magnetic resonance imaging (MRI), genotypic features and the therapeutic effect of uridine were analyzed. Results: A total of eight patients were enrolled. All patients presented with refractory epilepsy, anemia with anisopoikilocytosis and global developmental delay. The median age of epilepsy onset was 10 months, focal seizures were the most common. Anemia ranged from mild to severe. Patients had peripheral blood smears prior to uridine administration, showing erythrocytes of variable size and abnormal morphology, and normalized at a median time of 6 months after uridine supplementation. Cranial MRI were performed at seven patients, demonstrating cerebral and cerebellar atrophy. Six patients had cranial MRI re-examined after uridine treatment, indicating significant improvement in brain atrophy. Immediate cession of seizures was observed within days after uridine supplementation. Conclusions: The clinical manifestations of DEE50 present a triad of refractory epilepsy, anemia with anisopoikilocytosis, and psychomotor retardation, responsive to uridine treatment. Prompt diagnosis and immediate uridine supplementation could lead to significant clinical improvement.