title: Epilepsy is not a mandatory feature of STXBP1 associated ataxia-tremor-retardation syndrome.
abstract: BACKGROUND
  Mutations in the STXBP1 gene (MUNC18-1) were first described to cause Ohtahara syndrome (Early infantile epileptic encephalopathy, EIEE)(12-14) characterized by very early infantile epileptic encephalopathy with frequent tonic spasms and a suppression-burst pattern on electroencephalogram. In the following years a wider phenotype was recognized having milder forms of epilepsies. All patients showed also intellectual disability and movement disorders.
  
  
  METHODS
  Here, we present three female patients with an ataxia-tremor-retardation syndrome caused by a de novo STXBP1 mutation. Two of the girls were diagnosed through next-generation-sequencing as mutations in STXBP1 were not suspected. The third patient was diagnosed by targeted genetic testing due to its clinical features strikingly similar to the first two girls.
  
  
  RESULTS
  The characteristic feature of our three patients is the lack of epilepsy which is in contrast to the majority of the patients with STXBP1 mutation.
  
  
  CONCLUSIONS
  Hence, epilepsy is not a mandatory feature of patients with a STXBP1 mutation.
authors.affiliation: Department of Neuropaediatrics, Developmental Neurology, Social Paediatrics, University Children's Hospital Tübingen, Germany; Rare Disease Center Tübingen, University of Tübingen, Germany; Clinic for Paediatric Nephrology, Hepatology and Metabolic Disorders, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany. Electronic address: gburek-augustat.janina@mh-hannover.de.
authors.forename: Janina
authors.initials: J
authors.lastname: Gburek-Augustat
authors.affiliation: Department of Medical Genetics and Applied Genomics, University of Tübingen, Germany; Rare Disease Center Tübingen, University of Tübingen, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Beck-Woedl
authors.affiliation: Department of Medical Genetics and Applied Genomics, University of Tübingen, Germany; Rare Disease Center Tübingen, University of Tübingen, Germany; Institute of Clinical Genetics, University of Dresden, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Tzschach
authors.affiliation: Department of Medical Genetics and Applied Genomics, University of Tübingen, Germany; Rare Disease Center Tübingen, University of Tübingen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bauer
authors.affiliation: Department of Neuropaediatrics, Developmental Neurology, Social Paediatrics, University Children's Hospital Tübingen, Germany; Rare Disease Center Tübingen, University of Tübingen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schoening
authors.affiliation: Department of Medical Genetics and Applied Genomics, University of Tübingen, Germany; Rare Disease Center Tübingen, University of Tübingen, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Riess
mesh_terms: D001259:Ataxia / Q000235:genetics*; D002648:Child; D004569:Electroencephalography; D004827:Epilepsy / Q000235:genetics; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D051938:Munc18 Proteins / Q000235:genetics*; D009154:Mutation; D013577:Syndrome; D014202:Tremor / Q000235:genetics*
chemical_list: D051938:Munc18 Proteins; C497937:STXBP1 protein, human
keywords: Ataxia; Intellectual disability; STXBP1-mutation; Tremor