title: [Clinical features and PRRT2 gene mutation in paroxysmal kinesigenic dyskinesia].
abstract: OBJECTIVE
  To investigate the clinical features and proline-rich transmembrane protein 2 (PRRT2) gene mutation in patients with paroxysmal kinesigenic dyskinesia (PKD).
  
  
  METHODS
  Clinical information was collected at Peking University First Hospital from January 2004 to July 2014. In total, 10 patients with PKD were recruited, and all were males. Among them, four patients were the probands from four PKD families and the other six patients were sporadic cases. Clinical information was analyzed. Peripheral blood samples for DNA study were collected from PKD patients and their family members. Genomic DNA was extracted using standard procedures. Mutation analysis of PRRT2 was performed by Sanger sequencing after PCR.
  
  
  RESULTS
  Of the 10 patients, the median age of dyskinesias onset was 10 years, ranging from 4 to 13 years. The description of their attacks were abnormal involuntary movements provoked by sudden movements, without loss of consciousness. Five patients exhibited dystonia, two patients exhibited choreoathetosis, and three patients had mixed (dystonia and choreoathetosis) dyskinesias. The duration of the attacks lasted for 3 to 30 seconds. The frequency ranged from once per month to twenty times per day. PRRT2 mutations, c. 649_650insC (p. R217PfsX8), were found in all the four PKD families. Mutation c. 649_650insC was also detected in two of the six sporadic PKD cases, inheriting from their asymptomatic mother.
  
  
  CONCLUSIONS
  The onset age of PKD could be in the early childhood. The clinical features of the familial cases and sporadic cases showed no difference. The attacks manifested as dystonia, choreathetosis, or mixed. PRR2 mutations could be identified in familial or sporadic cases with PKD. Mutation c. 649_650insC is the hotspot mutation of PRRT2 gene.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Yang
authors.forename: Yuehua
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Xu
authors.forename: Zhixian
authors.initials: Z
authors.lastname: Yang
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.forename: Ye
authors.initials: Y
authors.lastname: Wu
authors.forename: Xiru
authors.initials: X
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D004421:Dystonia / Q000235:genetics*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*
chemical_list: D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C569370:PRRT2 protein, human