title: Novel PRRT2 mutation in an African-American family with paroxysmal kinesigenic dyskinesia.
abstract: BACKGROUND
  Recently, heterozygous mutations in PRRT2 (Chr 16p11.2) have been identified in Han Chinese, Japanese and Caucasians with paroxysmal kinesigenic dyskinesia. In previous work, a paroxysmal kinesigenic dyskinesia locus was mapped to Chr 16p11.2 - q11.2 in a multiplex African-American family.
  
  
  METHODS
  Sanger sequencing was used to analyze all four PRRT2 exons for sequence variants in 13 probands (9 Caucasian, 1 Caucasian-Thai, 1 Vietnamese and 2 African-American) with some form of paroxysmal dyskinesia.
  
  
  RESULTS
  One patient of mixed Caucasian-Thai background and one African-American family harbored the previously described hotspot mutation in PRRT2 (c.649dupC, p.R217Pfs*8). Another African-American family was found to have a novel mutation (c.776dupG, p.E260*). Both of these variants are likely to cause loss-of-function via nonsense-mediated decay of mutant PRRT2 transcripts. All affected individuals had classic paroxysmal kinesigenic dyskinesia phenotypes.
  
  
  CONCLUSIONS
  Heterozygous PRRT2 gene mutations also cause paroxysmal kinesigenic dyskinesia in African-Americans. The c.649dupC hotspot mutation in PRRT2 is common across racial groups.
authors.affiliation: Department of Neurology, Vanderbilt University, Nashville, TN, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Hedera
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Xiao
authors.forename: Andreas
authors.initials: A
authors.lastname: Puschmann
authors.forename: Dragana
authors.initials: D
authors.lastname: Momčilović
authors.forename: Steve W
authors.initials: SW
authors.lastname: Wu
authors.forename: Mark S
authors.initials: MS
authors.lastname: LeDoux
mesh_terms: D000328:Adult; D001741:Black or African American; D002819:Chorea / Q000208:ethnology / Q000235:genetics*; D004421:Dystonia; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D055815:Young Adult
chemical_list: D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C569370:PRRT2 protein, human