Mucopolysaccharidosis type III

Disease Overview

Mucopolysaccharidosis type III (MPS III) is a genetic disorder that makes the body unable to break down large sugar molecules called glycosaminoglycans (GAGs, formerly called mucopolysaccharides).[950][951] Specifically, people with this condition are unable to break down a GAG called heparan sulfate.[951] Affected individuals can have severe neurological symptoms, including progressive dementia, aggressive behavior, hyperactivity, seizures, deafness, loss of vision, and an inability to sleep for more than a few hours at a time.[950] MPS III is inherited in an autosomal recessive manner.[951] There is no specific treatment for this condition.[951] Most people with MPS III live into their teenage years, and some live longer.[950] 

MPS III is divided into four subtypes, known as A, B, C and D.[950][951] Each subtype is caused by the alteration of a different enzyme needed to completely break down heparan sulfate. The different types of MPS III have similar signs and symptoms, although type A is the most severe.[950][951]

To view the GARD pages on the subtypes of MPS III, click on the following links:

Mucopolysaccharidosis type IIIA
Mucopolysaccharidosis type IIIB
Mucopolysaccharidosis type IIIC
Mucopolysaccharidosis type IIID

Synonyms

• Mucopoly-saccharidosis type 3
• Sanfilippo syndrome
• MPSIII
• Mucopolysaccharidosis type 3
• Sanfilippo disease