This review offers an update on a group of inborn errors of metabolism causing severe epilepsy with the onset in pediatric age (but also other neurological manifestations such as developmental delay or movement disorders) with available effective or potentially effective treatments. The main pathogenic and clinical features and general recommendations for the diagnostic and therapeutic workup of the following disorders are discussed: vitamin B6-dependent epilepsies, cerebral folate deficiency, congenital disorders of serine metabolism, biotinidase deficiency, inborn errors of creatine metabolism, molybdenum cofactor deficiency, and glucose transporter 1 deficiency. Available treatments are more effective on epileptic manifestations (with the possibility of complete seizure control) and motor symptoms, whereas the benefits on cognitive outcome are usually minor.
Keywords: Cerebral folate deficiency; epileptic encephalopathies; inborn errors of creatine metabolism; metabolic epilepsy; pyridoxine-dependent seizures; serine metabolism disorders.