Hyaluronidase deficiency (also known as "Mucopolysaccharidosis type IX") is a condition caused by mutations in HYAL1, and characterized by multiple soft-tissue masses.
Sylvester Sanfilippo (January 1, 1926 – May 2, 2013) was a pediatrician from Edina, MN, who first described a mucopolysaccharide storage disease which bears his name.