A lysosomal storage disease with multisystemic involvement leading to a massive accumulation of glycosaminoglycans and a wide variety of symptoms including distinctive coarse facial features, short stature, cardio-respiratory involvement and skeletal abnormalities. It manifests as a continuum varying from a severe form with neurodegeneration to an attenuated form without neuronal involvement.

An intermittent cessation of airflow at the mouth and nose during sleep. Apneas of at least 10 seconds are considered important, but persons with sleep apnea may have apneas of 20 seconds to up to 2 or 3 minutes. Patients may have up to 15 events per hour of sleep.