Pyridoxine-dependent epilepsy
Pyridoxine-dependent epilepsy (PDE) is a rare autosomal recessive neurometabolic disease characterized by recurrent seizures that occur in infancy and, although resistant to antiepileptic drugs, do respond to pyridoxine, known as vitamin B6.
The prevalence of PDD is estimated to be between 1 in 20,000 and 1 in 783,000 live births.
Symptoms
Seizures usually appear in the neonatal period and are recurrent, it is thought that in some cases they may appear even before birth. They may also appear after two months of age and in more exceptional cases between one year and adolescence.
It is common for patients to develop intellectual disability, especially language impairment. An early onset of seizures and a delay in treatment may increase the risk of intellectual disability.
Disease management
Patients with PDE are treated with pyridoxine or vitamin B6 for life. The dose of pyridoxine is increased with age and may sometimes be temporarily increased to prevent exacerbation of seizures and encephalopathy.
Bibliography
Falsaperla R, Vari MS, Toldo I, et al . Pyridoxine-dependent epilepsies: an observational study on clinical, diagnostic, therapeutic and prognostic features in a pediatric cohort. Metab Brain Dis. 2018 Feb;33(1):261-269.
Gospe SM Jr. Pyridoxine-Dependent Epilepsy - ALDH7A1. 2001 Dec 7 [updated 2021 Jul 29]. In: Adam MP, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2022.
Plecko B, Paul K, Paschke E, et al . Biochemical and molecular characterization of 18 patients with pyridoxine-dependent epilepsy and mutations of the antichitin (ALDH7A1) gene. Hum Mutat. 2007 Jan;28(1):19-26.
Salomons GS, Bok LA, Struys EA, et al . An intriguing "silent" mutation and a founder effect in antiquitin (ALDH7A1). Ann Neurol. 2007 Oct;62(4):414-8.