A hereditary defect in mucopolysaccharide metabolism characterized by the excretion of dermatan sulfate and heparitin sulfate in the urine, abnormal development of skeletal cartilage and bone, corneal clouding, enlarged liver and spleen, mental retardation and sometimes deafness, and a coarsened facial surface with flattened nose and enlarged lips. Also called dysostosis multiplex, Hurler's disease, lipochondrodystrophy, type I mucopolysaccharidosis.