title: Risk of functional impairment in Facioscapulohumeral muscular dystrophy.
abstract: BACKGROUND
  Facioscapulohumeral muscular dystrophy (FSHD) is one of the most prevalent muscular dystrophies. Nevertheless, little is known about the risk of developing functional impairment. Here we determine the 6-year risk of functional impairment in FSHD.
  
  
  METHODS
  A retrospective cohort of 313 genetically confirmed, clinically affected FSHD participants in a United States registry between January 2002 and June 2011. Our main outcome was wheelchair (WC) use.
  
  
  RESULTS
  The 6-year risk of WC use was 24.0% (95% confidence interval 18.6-29.3). The distribution of WC risk was bimodal, with a peak in the second decade associated with large D4Z4 contractions, followed by an age-related increase in risk. Other functional categories showed moderate risk. Prevalence of hearing aid use and difficulty pronouncing words was increased in large D4Z4 contractions.
  
  
  CONCLUSIONS
  The 6-year risk of functional impairment in FSHD is moderate, and early WC use is associated with large D4Z4 contractions.
authors.affiliation: Department of Neurology, University of Rochester Medical Center, 265 Crittenden Boulevard, CU 420669, Rochester, New York, 14642-0669, USA.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Statland
authors.forename: Rabi
authors.initials: R
authors.lastname: Tawil
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020391:Muscular Dystrophy, Facioscapulohumeral / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014910:Wheelchairs / Q000706:statistics & numerical data
keywords: D4Z4 contraction; Facioscapulohumeral dystrophy; Functional impairment; Muscular dystrophy; Neuromuscular disorders