title: Scoring evaluation of the natural course of mucopolysaccharidosis type IIIA (Sanfilippo syndrome type A).
abstract: OBJECTIVE
  Mucopolysaccharidosis types IIIA through IIID (Sanfilippo syndrome) are caused by deficiencies of enzymes involved in the degradation of heparan sulfate. The onset and severity of the disease are highly variable. The purpose of this study was to describe the natural course of mucopolysaccharidosis type IIIA in a large cohort of patients.
  
  
  METHODS
  The natural course of mucopolysaccharidosis type IIIA was assessed in 71 patients by using a detailed questionnaire and a 4-point scoring system and compared with the course of the disease in 14 patients with mucopolysaccharidosis type IIIB and 4 patients with mucopolysaccharidosis type IIIC.
  
  
  RESULTS
  In the cohort of patients with mucopolysaccharidosis type IIIA, first symptoms of disease were observed, on average, at 7 months of age. Speech and motor development were delayed in 66.2% and 33.9% of patients, respectively. The median age at diagnosis was 4.5 years. The onset of regression in speech, motor, and cognitive function was observed at an average age of 3.3 years. The loss of all 3 of the assessed abilities was observed at an average age of 12.5 years. Speech was lost before motor and cognitive functions. In a small group of patients who were >12.5 years of age (9.9%), speech, motor, and cognitive skills were partially preserved up to a maximum age of 23.8 years.
  
  
  CONCLUSIONS
  To our knowledge, this is the first systematic and comprehensive study on the natural course of mucopolysaccharidosis type IIIA. The 4-point scoring system may be used to classify patients into groups with a rapid or slower course of the disease. This may have an important impact on parental counseling as well as therapeutic interventions.
authors.affiliation: University Medical Center Hamburg-Eppendorf, Metabolic Center, Department of Pediatrics, Martinistrasse 52, Building N23, 20246 Hamburg, Germany.
authors.forename: Ann
authors.initials: A
authors.lastname: Meyer
authors.forename: Kai
authors.initials: K
authors.lastname: Kossow
authors.forename: Andreas
authors.initials: A
authors.lastname: Gal
authors.forename: Chris
authors.initials: C
authors.lastname: Mühlhausen
authors.forename: Kurt
authors.initials: K
authors.lastname: Ullrich
authors.forename: Thomas
authors.initials: T
authors.lastname: Braulke
authors.forename: Nicole
authors.initials: N
authors.lastname: Muschol
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009084:Mucopolysaccharidosis III / Q000145:classification* / Q000175:diagnosis / Q000473:pathology*; D012107:Research Design; D011795:Surveys and Questionnaires