title: Myopathy in Childhood Muscle-Specific Kinase Myasthenia Gravis.
abstract: Adult and pediatric patients suffering from MuSK (muscle-specific kinase) -antibody positive myasthenia gravis exhibit similar features to individuals with acetylcholine receptor (AChR) antibodies, but they differ in several characteristics such as a predominant bulbar, respiratory and neck weakness, a generally worse disease severity and a tendency to develop muscle atrophy. Muscle atrophy is a rare phenomenon that is usually restricted to the facial muscles.
  
  
  
  We describe a girl with MuSK-antibody positive myasthenia gravis who developed a myopathy with severe generalized muscular weakness, muscle atrophy, and myopathic changes on electromyography.
  
  
  
  This is the first published example of a generalized myopathic syndrome in myasthenia gravis. We review the relevant literature and discuss the hypothesis of a mitochondrial myopathy as a pathogenic mechanism in MuSK-antibody positive myasthenia gravis.
authors.affiliation: Department of Neurology, University of Regensburg, Regensburg, Germany. Electronic address: lukas.kirzinger@medbo.de.
authors.forename: Lukas
authors.initials: L
authors.lastname: Kirzinger
authors.affiliation: Department of Neurology, University of Regensburg, Regensburg, Germany.
authors.forename: Andrei
authors.initials: A
authors.lastname: Khomenko
authors.affiliation: Department of Neurology, University of Regensburg, Regensburg, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Schulte-Mattler
authors.affiliation: Department of Neurology, University of Regensburg, Regensburg, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Backhaus
authors.affiliation: Department of Neurology, University of Regensburg, Regensburg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Platen
authors.affiliation: Department of Neurology, University of Regensburg, Regensburg, Germany.
authors.forename: Berthold
authors.initials: B
authors.lastname: Schalke
mesh_terms: D002648:Child; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000008:administration & dosage; D009135:Muscular Diseases / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy; D009157:Myasthenia Gravis / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy; D020794:Receptor Protein-Tyrosine Kinases / Q000097:blood*; D011950:Receptors, Cholinergic / Q000097:blood*; D013256:Steroids / Q000008:administration & dosage
chemical_list: D016756:Immunoglobulins, Intravenous; D011950:Receptors, Cholinergic; D013256:Steroids; C095714:MUSK protein, human; D020794:Receptor Protein-Tyrosine Kinases
keywords: MuSK; autoimmunity; childhood myasthenia; myasthenia gravis; myopathy