title: Epsilon sarcoglycan mutations and phenotype in French patients with myoclonic syndromes.
abstract: BACKGROUND
  Myoclonus dystonia syndrome (MDS) is an autosomal dominant movement disorder caused by mutations in the epsilon-sarcoglycan gene (SGCE) on chromosome 7q21.
  
  
  METHODS
  We have screened for SGCE mutations in index cases from 76 French patients with myoclonic syndromes, including myoclonus dystonia (M-D), essential myoclonus (E-M), primary myoclonic dystonia, generalised dystonia, dystonia with tremor, and benign hereditary chorea. All coding exons of the SGCE gene were analysed. The DYT1 mutation was also tested.
  
  
  RESULTS
  Sixteen index cases had SGCE mutations while one case with primary myoclonic dystonia carried the DYT1 mutation. Thirteen different mutations were found: three nonsense mutations, three missense mutations, three splice site mutations, three deletions, and one insertion. Eleven of the SGCE index cases had M-D and five E-M. No SGCE mutations were detected in patients with other phenotypes. The total number of mutation carriers in the families was 38, six of whom were asymptomatic. Penetrance was complete in paternal transmissions and null in maternal transmissions. MDS patients with SGCE mutation had a significantly earlier onset than the non-carriers. None of the patients had severe psychiatric disorders.
  
  
  CONCLUSIONS
  This large cohort of index patients shows that SGCE mutations are primarily found in patients with M-D and to a lesser extent E-M, but are present in only 30% of these patients combined (M-D and E-M).
authors.affiliation: Service de Biostatistique et Information Medicale, Hôpital Pitié-Salpêtrière, AP-HP, Paris, France. sophie.tezenas@psl.aphp.fr
authors.forename: S
authors.initials: S
authors.lastname: Tezenas du Montcel
authors.forename: F
authors.initials: F
authors.lastname: Clot
authors.forename: M
authors.initials: M
authors.lastname: Vidailhet
authors.forename: E
authors.initials: E
authors.lastname: Roze
authors.forename: P
authors.initials: P
authors.lastname: Damier
authors.forename: C P
authors.initials: CP
authors.lastname: Jedynak
authors.forename: A
authors.initials: A
authors.lastname: Camuzat
authors.forename: A
authors.initials: A
authors.lastname: Lagueny
authors.forename: L
authors.initials: L
authors.lastname: Vercueil
authors.forename: D
authors.initials: D
authors.lastname: Doummar
authors.forename: L
authors.initials: L
authors.lastname: Guyant-Maréchal
authors.forename: J-L
authors.initials: JL
authors.lastname: Houeto
authors.forename: G
authors.initials: G
authors.lastname: Ponsot
authors.forename: S
authors.initials: S
authors.lastname: Thobois
authors.forename: M-A
authors.initials: MA
authors.lastname: Cournelle
authors.forename: A
authors.initials: A
authors.lastname: Durr
authors.forename: F
authors.initials: F
authors.lastname: Durif
authors.forename: B
authors.initials: B
authors.lastname: Echenne
authors.forename: D
authors.initials: D
authors.lastname: Hannequin
authors.forename: C
authors.initials: C
authors.lastname: Tranchant
authors.forename: A
authors.initials: A
authors.lastname: Brice
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002819:Chorea / Q000175:diagnosis / Q000235:genetics; D002897:Chromosomes, Human, Pair 7; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D020821:Dystonic Disorders / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D005602:France; D005820:Genetic Testing; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D018832:Molecular Chaperones / Q000235:genetics; D009154:Mutation; D009207:Myoclonus / Q000175:diagnosis* / Q000235:genetics; D010641:Phenotype; D049031:Sarcoglycans / Q000235:genetics*; D013577:Syndrome
chemical_list: D018832:Molecular Chaperones; D049031:Sarcoglycans; C108175:TOR1A protein, human