title: Guanidinoacetate methyltransferase (GAMT) deficiency: a rare but treatable epilepsy.
abstract: Epilepsy commonly presents in childhood as part of a syndrome, and some such children may reach adult services without an underlying syndromic diagnosis. For adult neurologists taking over their care, it is often unclear how hard to search for an underlying diagnosis. The diagnostic yield may be small and such a diagnosis may not change management. Young adults with learning difficulties are also challenging to investigate, as they may not tolerate standard epilepsy tests.We present such a case in which simple tests identified a unifying diagnosis. With the new diagnosis came a new treatment that had a significant impact on seizures and quality of life.
authors.affiliation: Department of Clinical and Experimental Epilepsy, NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, London, UK.|Epilepsy Society, London, UK.
authors.forename: William M
authors.initials: WM
authors.lastname: Stern
authors.affiliation: Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, UK.|Department of Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
authors.forename: Joel S
authors.initials: JS
authors.lastname: Winston
authors.affiliation: Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK.
authors.forename: Elaine
authors.initials: E
authors.lastname: Murphy
authors.affiliation: Institute of Child Health, UCL, London, UK.
authors.forename: J Helen
authors.initials: JH
authors.lastname: Cross
authors.affiliation: Department of Clinical and Experimental Epilepsy, NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, London, UK.|Epilepsy Society, London, UK.|Stichting Epilepsie Instellingen Nederland (SEIN), Netherlands, UK.
authors.forename: Josemir W
authors.initials: JW
authors.lastname: Sander
mesh_terms: D000328:Adult; D003401:Creatine / Q000097:blood / Q000627:therapeutic use / Q000652:urine; D004827:Epilepsy / Q000209:etiology* / Q000628:therapy*; D050937:Guanidinoacetate N-Methyltransferase / Q000097:blood / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism / Q000652:urine; D006801:Humans; D007805:Language Development Disorders / Q000150:complications* / Q000235:genetics / Q000378:metabolism; D008297:Male; D009069:Movement Disorders / Q000150:complications / Q000151:congenital* / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics
chemical_list: D050937:Guanidinoacetate N-Methyltransferase; D003401:Creatine