Early onset epilepsy with resistance to common anticonvulsants can be due to genetic defects that respond to high doses of vitamin B6. We describe four patients with neonatal, pyridoxine (vitamin B6) responsive seizures and disease causing variants in the PROSC gene, which regulates vitamin B6 metabolism in body cells. Three patients had favorable outcome with normal intellectual properties at age 12.5, 15.5 and 30 years respectively, while one child had marked developmental delay at age 27 months. Prognosis of patients depends on early treatment with vitamin B6, an essential cofactor for normal brain function, and the underlying PROSC variants. (By Prof. Dr. Barbara Plecko, http://jmg.bmj.com/content/early/2017/04/07/jmedgenet-2017-104521 )