Clinical and genetic characteristics of pyridoxine-dependent epilepsy: Case series report of three Chinese patients with phenotypic variability.

Pyridoxine-dependent epilepsy (PDE) is a rare disorder caused by aldehyde dehydrogenase 7 family member A1 (ALDH7A1) deficiency. The present study reported on three Chinese cases of PDE with phenotypic variability for providing further insight into this disease. All three patients presented with recurrent seizures and readily responded to treatment with pyridoxine, in line with the typical symptomology of PDE. The three cases varied in their clinical manifestations with regard to the time of onset, seizure type, EEG findings and mental development. Four ALDH7A1 mutations were identified in Case 1 (c.1008+1G>A and c.871+5G>A) and Case 2 (c.977A>G and c.1463A>G). To the best of our knowledge, the present study was the first to report on the mutations c.871+5G>A and c.1463A>G. Early definitive diagnosis and timely treatment with pyridoxine was the cornerstone of management of PDE. Timely treatment was associated with excellent prognosis. A high index of suspicion in cases and early genetic testing may facilitate early diagnosis of this rare disease.