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.

Deep, noisy breathing during sleep accompanied by hoarse or harsh sounds caused by the vibration of respiratory structures (especially the soft palate) resulting in sound due to obstructed air movement during breathing while sleeping.