Mondo Description Mucopolysaccharidosis type IV (MPS IV) is a lysosomal storage disease belonging to the group of mucopolysaccharidoses, and characterised by spondylo-epiphyso-metaphyseal dysplasia. It exists in two forms, A and B.

Disease Ontology Description A mucopolysaccharidosis characterized by a deficiency of the lysosomal enzymes galactose 6-sulfate sulfatase (Type A) or beta-galactosidase (Type B) needed to break down the keratan sulfate sugar chain.