title: Functional magnetic resonance imaging evidence of incomplete maternal imprinting in myoclonus-dystonia.
abstract: BACKGROUND
  Myoclonus-dystonia is an autosomal dominantly inherited movement disorder, clinically characterized by myoclonic jerks and dystonic postures or movements. A previous functional magnetic resonance imaging study showed altered cortical activation patterns in clinically affected SGCE mutation carriers when compared with controls consistent with defective sensorimotor integration. Genetically, the disorder is characterized by the maternal imprinting mechanism; ie, patients who inherit the mutation from their fathers will develop symptoms. However, several clinically manifest patients with myoclonus-dystonia who inherited the mutation from their mother have been described.
  
  
  OBJECTIVE
  To compare cerebral activation patterns of paternally inherited SGCE mutation carriers are with maternally inherited mutation carriers and a control group.
  
  
  METHODS
  Case-control study using functional magnetic resonance imaging.
  
  
  METHODS
  Eight paternally inherited SGCE mutation carriers, 8 asymptomatic or slightly affected (4 of 8) symptomatic maternally inherited mutation carriers, and 11 control subjects.
  
  
  METHODS
  Participants were studied using a 3-T functional magnetic resonance imaging scanner with a finger tapping task.
  
  
  RESULTS
  When paternal and maternal gene mutation carriers were compared, hyperresponsiveness was seen in the contralateral secondary somatosensory cortex. When maternal mutation carriers and control subjects were compared, hyperresponsiveness of the ipsilateral cerebellum and supplementary motor area were found. Using a nonparametric analysis to study only the 4 clinically asymptomatic patients, no significant differences were found between groups. Contrast estimates were plotted for the known affected sensorimotor brain areas, showing intermediate activation in maternally inherited mutation carriers, even when this was performed for only the 4 clinically unaffected mutation carriers.
  
  
  CONCLUSIONS
  The results suggest biased gene expression based on parent of origin rather than a strictly dichotomous maternal imprinting mechanism, consistent with clinical observations.
authors.affiliation: Department of Neurology, Academic Medical Centre, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, The Netherlands.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Beukers
authors.forename: Elisabeth M J
authors.initials: EM
authors.lastname: Foncke
authors.forename: Johan N
authors.initials: JN
authors.lastname: van der Meer
authors.forename: Dick J
authors.initials: DJ
authors.lastname: Veltman
authors.forename: Marina A J
authors.initials: MA
authors.lastname: Tijssen
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D020821:Dystonic Disorders / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D019317:Evidence-Based Medicine; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D018392:Genomic Imprinting / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049031:Sarcoglycans / Q000235:genetics*; D055815:Young Adult
chemical_list: C526572:SGCE protein, human; D049031:Sarcoglycans