title: Novel heteroplasmic mutation in the anticodon stem of mitochondrial tRNA(Lys) associated with dystonia and stroke-like episodes.
abstract: OBJECTIVE
  We report a novel heteroplasmic mitochondrial tRNA(Lys) mutation associated with dystonia, stroke-like episodes, sensorineural hearing loss and epilepsy in a Hungarian family.
  
  
  METHODS
  A 16-year-old boy, his brother and mother were investigated. Thorough clinical investigation as well as electrophysiological, neuroradiological and myopathological examinations were performed. Molecular studies included the analysis of the DYT1, DDP1/TIMM8A (deafness-dystonia peptid-1) genes and mitochondrial DNA (mtDNA).
  
  
  RESULTS
  The mtDNA analysis of the proband revealed a heteroplasmic A8332G substitution in the anticodon stem of the tRNA(Lys) gene. The mutation segregated in all affected family members. Besides this mutation 16 further mtDNA polymorphisms were detected. Complex I activity of the patient's fibroblast cultures showed decreased activity confirming mitochondrial dysfunction.
  
  
  CONCLUSIONS
  The novel A8332G heteroplasmic mutation is most likely a new cause of dystonia and stroke-like episodes due to mitochondrial encephalopathy. The synergistic effect of the G8697A, A11812G and T10463C single nucleotide polymorphisms may modify the phenotype.
authors.affiliation: Clinical and Research Centre of Molecular Neurology, Semmelweis University, Budapest, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Gal
authors.forename: K
authors.initials: K
authors.lastname: Pentelenyi
authors.forename: V
authors.initials: V
authors.lastname: Remenyi
authors.forename: Z
authors.initials: Z
authors.lastname: Pal
authors.forename: B
authors.initials: B
authors.lastname: Csanyi
authors.forename: G
authors.initials: G
authors.lastname: Tomory
authors.forename: I
authors.initials: I
authors.lastname: Rasko
authors.forename: M J
authors.initials: MJ
authors.lastname: Molnar
mesh_terms: D000293:Adolescent; D000926:Anticodon / Q000235:genetics*; D004421:Dystonia / Q000235:genetics*; D004827:Epilepsy / Q000235:genetics; D006319:Hearing Loss, Sensorineural / Q000235:genetics; D006801:Humans; D006814:Hungary; D008297:Male; D008928:Mitochondria / Q000235:genetics*; D009154:Mutation; D010375:Pedigree; D011110:Polymorphism, Genetic; D012343:RNA, Transfer / Q000235:genetics*; D020521:Stroke / Q000235:genetics*
chemical_list: D000926:Anticodon; D012343:RNA, Transfer