An inborn error of metabolism characterized by beta-glucuronidase (EC 3.2.1.31) deficiency with abnormal storage of mucopolysaccharides in various tissues. The phenotype consists mainly of short stature, hepatosplenomegaly, dysostosis multiplex, and mild mental retardation. Type I is the most severe with hydrops fetalis, coarse facies with hypertelorism and depressed nasal bridge, cloudy corneae, and onset of symptoms at birth. Type II has a less severe course with moderate Huurler facies and hypertelorism and onset at 2 to 3 years. Type III has the mildest symptoms with onset during adolescence.