title: The natural history of MPS I: global perspectives from the MPS I Registry.
abstract: OBJECTIVE
  In this study, we aimed to describe the natural history of mucopolysaccharidosis I.
  
  
  METHODS
  Data from 1,046 patients who enrolled in the MPS I Registry as of August 2013 were available for descriptive analysis. Only data from untreated patients and data prior to treatment for patients who received treatment were considered. Age at symptom onset, diagnosis, and treatment initiation were examined by geographic region and phenotype (from most to least severe: Hurler, Hurler-Scheie, and Scheie). For each symptom, frequency and age at onset were examined.
  
  
  RESULTS
  Natural history data were available for 987 patients. Most patients were from Europe (45.5%), followed by North America (34.8%), Latin America (17.3%), and Asia Pacific (2.4%). Phenotype distribution was 60.9% for Hurler, 23.0% for Hurler-Scheie, and 12.9% for Scheie (3.2% undetermined) syndromes. Median age at symptom onset for Hurler, Hurler-Scheie, and Scheie syndromes was 6 months, 1.5 years, and 5.3 years, respectively; median age at treatment initiation was 1.5 years, 8.0 years, and 16.9 years, respectively. Coarse facial features and corneal clouding were among the most common symptoms in all three phenotypes.
  
  
  CONCLUSIONS
  A delay between symptom onset and treatment exists, especially in patients with attenuated mucopolysaccharidosis I. A better understanding of disease manifestations may help facilitate prompt diagnosis and treatment and improve patient outcomes.
authors.affiliation: Children's Hospital, University of Mainz, Mainz, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Beck
authors.affiliation: The Nemours Children's Clinic, Jacksonville, Florida, USA.
authors.forename: Pamela
authors.initials: P
authors.lastname: Arn
authors.affiliation: Department of Genetics UFRGS and INAGEMP, Medical Genetics Service/HCPA, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Giugliani
authors.affiliation: University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Muenzer
authors.affiliation: National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Torayuki
authors.initials: T
authors.lastname: Okuyama
authors.affiliation: Genzyme, a Sanofi company, Cambridge, Massachusetts, USA.
authors.forename: John
authors.initials: J
authors.lastname: Taylor
authors.affiliation: Genzyme, a Sanofi company, Cambridge, Massachusetts, USA.
authors.forename: Shari
authors.initials: S
authors.lastname: Fallet
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001208:Asia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005060:Europe / Q000453:epidemiology; D005260:Female; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D007223:Infant; D007843:Latin America / Q000453:epidemiology; D008297:Male; D008059:Mucopolysaccharidosis I / Q000453:epidemiology / Q000235:genetics* / Q000628:therapy; D009656:North America / Q000453:epidemiology; D010641:Phenotype; D015995:Prevalence; D012042:Registries / Q000706:statistics & numerical data*