A clinical syndrome of psychomotor retardation, spastic paraplegia, cerebellar ataxia and dyskinesia associated with low cerebrospinal fluid (CSF) concentrations of 5-methyltetrahydrofolate and normal folate concentrations in plasma and red blood cells was described by Ramaekers and colleagues in 2002 and given the name cerebral folate deficiency syndrome (CFDS). The onset of symptoms and signs is usually 4–6 months after birth and seizures and autistic features may develop. Treatment is with pharmacological doses of …