title: Sodium and chloride channelopathies with myositis: coincidence or connection?
abstract: BACKGROUND
  A proximal myopathy develops in some patients with muscle channelopathies, but the causative molecular mechanisms are unknown.
  
  
  METHODS
  We reviewed retrospectively all clinical and muscle biopsy findings of 3 patients with channelopathy and additional myositis. Direct DNA sequencing was performed.
  
  
  RESULTS
  Pathogenic mutations were identified in each case. Biopsies demonstrated inflammatory infiltrates.
  
  
  CONCLUSIONS
  Clinicians should consider muscle biopsy in channelopathy patients with severe myalgia and/or subacute weakness and accompanying elevated creatine kinase. Chance association of myositis and channelopathy is statistically unlikely. An alternative hypothesis suggests that inflammatory insults could contribute to myopathy in some patients.
authors.affiliation: Medical Research Council Centre for Neuromuscular Disease, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK.
authors.forename: Emma
authors.initials: E
authors.lastname: Matthews
authors.forename: James A L
authors.initials: JA
authors.lastname: Miller
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: MacLeod
authors.forename: James
authors.initials: J
authors.lastname: Ironside
authors.forename: Gareth
authors.initials: G
authors.lastname: Ambler
authors.forename: Robin
authors.initials: R
authors.lastname: Labrum
authors.forename: Richa
authors.initials: R
authors.lastname: Sud
authors.forename: Janice L
authors.initials: JL
authors.lastname: Holton
authors.forename: Michael G
authors.initials: MG
authors.lastname: Hanna
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D053447:Channelopathies / Q000235:genetics* / Q000473:pathology; D018118:Chloride Channels / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D018908:Muscle Weakness / Q000235:genetics / Q000473:pathology; D009132:Muscles / Q000473:pathology; D009220:Myositis / Q000235:genetics* / Q000473:pathology; D015222:Sodium Channels / Q000235:genetics*
chemical_list: D018118:Chloride Channels; D015222:Sodium Channels