title: Clinical and molecular features of encephalomyopathy due to the A3302G mutation in the mitochondrial tRNA(Leu(UUR)) gene.
abstract: BACKGROUND
  The mitochondrial DNA mutation A3302G in the tRNA(Leu(UUR)) gene causes respiratory chain complex I deficiency. The main clinical feature appears to be a progressive mitochondrial myopathy with proximal muscle weakness.
  
  
  OBJECTIVE
  To report on clinical and molecular features in 4 novel patients with the A3302G mutation.
  
  
  METHODS
  Case reports.
  
  
  METHODS
  Four patients (3 of whom are from the same family) with a myopathy caused by the A3302G mitochondrial DNA mutation.
  
  
  METHODS
  Identification of the A3302G mutation by DNA sequencing.
  
  
  RESULTS
  All 4 patients had an adult-onset progressive mitochondrial myopathy with proximal muscle weakness, resulting in exercise intolerance. In 2 unrelated patients, upper limb reflexes were absent with preservation of at least some lower limb reflexes. Other features including hearing loss, recurrent headaches, ptosis, progressive external ophthalmoplegia, and depression were present.
  
  
  CONCLUSIONS
  While the dominant clinical features of the A3302G mutation were exercise intolerance and proximal muscle weakness, other features of mitochondrial encephalomyopathies, previously not described for this mutation, were present.
authors.affiliation: Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia.
authors.forename: Wendy M
authors.initials: WM
authors.lastname: Hutchison
authors.forename: Dominic
authors.initials: D
authors.lastname: Thyagarajan
authors.forename: Joanna
authors.initials: J
authors.lastname: Poulton
authors.forename: David R
authors.initials: DR
authors.lastname: Marchington
authors.forename: Denise M
authors.initials: DM
authors.lastname: Kirby
authors.forename: Shehnaaz S M
authors.initials: SS
authors.lastname: Manji
authors.forename: Hans-Henrik M
authors.initials: HH
authors.lastname: Dahl
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D004252:DNA Mutational Analysis; D003866:Depressive Disorder / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D004579:Electron Transport / Q000235:genetics; D017079:Exercise Tolerance / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing; D006261:Headache / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D034381:Hearing Loss / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D008297:Male; D017237:Mitochondrial Encephalomyopathies / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009154:Mutation / Q000235:genetics*; D015835:Ocular Motility Disorders / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D012313:RNA / Q000235:genetics*; D000077278:RNA, Mitochondrial; D012356:RNA, Transfer, Leu / Q000235:genetics*; D012021:Reflex, Abnormal / Q000235:genetics
chemical_list: D000077278:RNA, Mitochondrial; D012356:RNA, Transfer, Leu; D012313:RNA