mucopolysaccharidosis type I

Last reviewed 01/2018

This is a lysosomal storage disease caused by deficiency of alpha-L-iduronidase. There is a spectrum of severity:

  • Hurler syndrome (MPS IH) is the severe form
  • Scheie syndrome (MPS IS) is the mild form

The severe forms present before age 2 and progress rapidly with prominent intellectual decline. Hydrocephalus may be present in mild and severe forms.

Hepatomegaly causes abdominal distension. There is prominent dysostosis and arthropathy. Cardiac involvement may be severe.