title: Psychiatric disorders, myoclonus dystonia and SGCE: an international study.
abstract: Myoclonus-dystonia (M-D) is a hyperkinetic movement disorder, typically alcohol-responsive upper body myoclonus and dystonia. The majority of autosomal dominant familial cases are caused by epsilon-sarcoglycan gene (SGCE) mutations. Previous publications have observed increased rates of psychiatric disorders amongst SGCE mutation-positive populations. We analyzed the psychiatric data from four international centers, forming the largest cohort to date, to further determine the extent and type of psychiatric disorders in M-D.
  
  
  
  Psychiatric data from SGCE mutation-positive M-D cohorts, collected by movement disorder specialists in the Netherlands, United Kingdom, United States, and Germany, were analyzed. These data were collected using standardized, systematic questionnaires allowing classification of symptoms according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) criteria. Based on motor findings and SGCE mutation analysis, participants were classified into one of three groups: manifesting carriers, nonmanifesting carriers and noncarriers.
  
  
  
  Data from 307 participants were evaluated (140 males, 167 females, mean age at examination: 42.5 years). Two-thirds of motor affected mutation carriers (n = 132) had ≥1 psychiatric diagnosis, specific, and social phobias being most common followed by alcohol dependence and obsessive-compulsive disorder (OCD). Compared to familial controls, affected mutation carriers had significantly elevated overall rates of psychiatric disorders (P < 0.001). The most significant differences were observed with alcohol dependence (P < 0.001), OCD (P < 0.001), social and specific phobias (P < 0.001).
  
  
  
  M-D due to SGCE mutations is associated with specific psychiatric disorders, most commonly OCD, anxiety-related disorders, and alcohol dependence. These suggest either a potential pleiotropic function for SGCE within the central nervous system or a secondary effect of the motor disorder.
authors.affiliation: Department of Neurology University Medical Center Groningen Groningen The Netherlands; Institute of Psychological Medicine and Clinical Neurosciences MRC Centre for Neuropsychiatric Genetics and Genomics Cardiff University Cardiff United Kingdom.
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Peall
authors.affiliation: Department of Neurology The Academic Medical Center Amsterdam The Netherlands.
authors.forename: Joke M
authors.initials: JM
authors.lastname: Dijk
authors.affiliation: The Saul R. Korey Department of Neurology Beth Israel Medical Centre New York.
authors.forename: Rachel
authors.initials: R
authors.lastname: Saunders-Pullman
authors.affiliation: Department of Neurology The Academic Medical Center Amsterdam The Netherlands.
authors.forename: Yasmine E M
authors.initials: YE
authors.lastname: Dreissen
authors.affiliation: Department of Neurology The Academic Medical Center Amsterdam The Netherlands.
authors.forename: Ilke
authors.initials: I
authors.lastname: van Loon
authors.affiliation: Department of Behavioural Sciences - Clinical and Health Psychology University of Utrecht Utrecht The Netherlands.
authors.forename: Danielle
authors.initials: D
authors.lastname: Cath
authors.affiliation: Institute of Child Health - Neurosciences Unit University College London London United Kingdom; Department of Neurology Great Ormond Street Hospital London United Kingdom.
authors.forename: Manju A
authors.initials: MA
authors.lastname: Kurian
authors.affiliation: Institute of Psychological Medicine and Clinical Neurosciences MRC Centre for Neuropsychiatric Genetics and Genomics Cardiff University Cardiff United Kingdom.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Owen
authors.affiliation: Department of Neurology The Academic Medical Center Amsterdam The Netherlands.
authors.forename: Elisabeth M J
authors.initials: EM
authors.lastname: Foncke
authors.affiliation: Institute of Psychological Medicine and Clinical Neurosciences MRC Centre for Neuropsychiatric Genetics and Genomics Cardiff University Cardiff United Kingdom.
authors.forename: Huw R
authors.initials: HR
authors.lastname: Morris
authors.affiliation: Department for Neurodegenerative Diseases Hertie Institute for Clinical Brain Research Tubingen Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gasser
authors.affiliation: The Saul R. Korey Department of Neurology Beth Israel Medical Centre New York.
authors.forename: Susan
authors.initials: S
authors.lastname: Bressman
authors.affiliation: Department for Neurodegenerative Diseases Hertie Institute for Clinical Brain Research Tubingen Germany.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Asmus
authors.affiliation: Department of Neurology University Medical Center Groningen Groningen The Netherlands.
authors.forename: Marina A J
authors.initials: MA
authors.lastname: Tijssen