Mucopolysaccharides are long chains of sugar molecules that are found throughout the body, often in mucus and in fluid around the joints. They are more commonly called glycosaminoglycans.

Glycosaminoglycans; GAG

When the body cannot break down mucopolysaccharides, a condition called mucopolysaccharidoses (MPS) occurs. MPS refers to a group of inherited disorders of metabolism. People with MPS do not have any, or enough of, a substance (enzyme) needed to break down the sugar molecule chains.

Forms of MPS include:

• Hunter syndrome
• Hurler syndrome
• Sanfilippo syndrome
• Scheie syndrome
• Morquio syndrome

These conditions cause mucopolysaccharides to build up in body tissues. This can damage organs, including the heart. Symptoms can range from mild to severe and may include:

• Abnormal features of the face
• Bone, cartilage, and connective tissue deformities
• Intellectual disability

National Institute of Neurological Disorders and Stroke. Mucolipidoses Fact Sheet. Bethesda, MD: Office of Communications and Public Liaison; February 13, 2007. Publication No. 03-5115.