title: Spasmodic dysphonia in a patient with the A to G transition at nucleotide 8344 in mitochondrial DNA.
abstract: Dystonia has been described in various diseases affecting mitochondrial function but spasmodic dysphonia, a form of focal dystonia, has not. We present a patient with action myoclonus affecting the hands and arms who carried the most common mutation in mitochondrial DNA causing the myoclonic epilepsy and ragged red fibers (MERRF) syndrome (the A-->G substitution at nucleotide 8344 in the tRNA(Lys) gene). This patient also had spasmodic dysphonia that was responsive to treatment with intralaryngeal botulinum toxin.
authors.affiliation: Department of Pediatrics, University of California at Irvine, Orange, California 92868, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Peng
authors.forename: Roger
authors.initials: R
authors.lastname: Crumley
authors.forename: John M
authors.initials: JM
authors.lastname: Ringman
mesh_terms: D004272:DNA, Mitochondrial / Q000378:metabolism*; D004831:Epilepsies, Myoclonic / Q000150:complications; D005260:Female; D006801:Humans; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000150:complications* / Q000235:genetics*; D009154:Mutation; D009207:Myoclonus / Q000150:complications; D010375:Pedigree; D018709:Statistics, Nonparametric; D014832:Voice Disorders / Q000235:genetics* / Q000378:metabolism*
chemical_list: D004272:DNA, Mitochondrial