Personer med MPS I har et lavt niveau eller intet niveau af et enzym, der hedder α- L- iduronidase, som nedbryder bestemte stoffer (glykosaminoglycaner) i kroppen.
People with MPS I disease have either a low level or no level of an enzyme called α -L-iduronidase, which breaks down specific substances (glycosaminoglycans) in the body.