title: Diagnostic value of mitochondrial DNA mutation analysis in juvenile unilateral ptosis.
abstract: OBJECTIVE
  To highlight the diagnostic relevance of mitochondrial DNA (mtDNA) mutation analysis in acquired juvenile unilateral upper eyelid ptosis.
  
  
  METHODS
  A 13-year-old boy presented with acquired, slowly progressive unilateral ptosis. We performed ophthalmological and neurological examinations, laboratory testing, skeletal muscle biopsy including histological and histochemical investigations, biochemical analysis of respiratory chain enzymes in skeletal muscle homogenate and molecular genetic testing of skeletal muscle DNA.
  
  
  RESULTS
  Though clinical, laboratory, histological and biochemical analyses did not reveal any hints suggesting a mitochondrial cytopathy, molecular genetic testing by Southern blot analysis of total DNA from skeletal muscle tissue showed a 5.8 kb mtDNA deletion thus proving the diagnosis of mitochondrial chronic progressive external ophthalmoplegia (CPEO).
  
  
  CONCLUSIONS
  In patients with unexplained acquired juvenile unilateral ptosis, an underlying mitochondrial cytopathy should be considered even in cases of inconspicuous ancillary examinations comprising skeletal muscle histology and biochemistry. To establish the diagnosis, molecular genetic testing of DNA derived from skeletal muscle tissue is essential in those patients.
authors.affiliation: Department of Neurology, University of Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Okulla
authors.forename: Wolfram S
authors.initials: WS
authors.lastname: Kunz
authors.forename: Thomas
authors.initials: T
authors.lastname: Klockgether
authors.forename: Rolf
authors.initials: R
authors.lastname: Schröder
authors.forename: Cornelia
authors.initials: C
authors.lastname: Kornblum
mesh_terms: D000293:Adolescent; D001763:Blepharoptosis / Q000175:diagnosis* / Q000235:genetics; D015139:Blotting, Southern; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D006801:Humans; D008297:Male; D008931:Mitochondria, Muscle / Q000235:genetics; D018482:Muscle, Skeletal / Q000473:pathology; D009154:Mutation; D017246:Ophthalmoplegia, Chronic Progressive External / Q000175:diagnosis* / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial