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Mucopolysaccharidosis type IIIA

Other Names for this Disease
  • Heparan sulfate sulfatase deficiency
  • MPS 3A
  • Mucopoly-saccharidosis type 3A
  • Sanfilippo syndrome A
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Mucopolysaccharidosis type IIIA (MPS IIIA) is an genetic disorder that makes the body unable to break down large sugar molecules called glycosaminoglycans (GAGs, formerly called mucopolysaccharides).[1][2] MPS IIIA is the most severe of the MPS III disorders and children with this condition have the shortest survival rate among those with the MPS III disorders.[1] Individuals with this condition are unable to break down a GAG called heparan sulfate.[2] 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.[1] MPS IIIA is caused by the missing or altered enzyme heparan N-sulfatase. MPS IIIA is inherited in an autosomal recessive manner. There is no specific treatment for this condition.[1][2]
Last updated: 4/14/2010


  1. Mucopolysaccharidoses Fact Sheet. National Institute of Neurological Disorders and Stroke Website. February 16, 2010; Accessed 4/14/2010.
  2. Chambers D. Sanfilippo syndrome. Medline Plus Web site. May 11, 2009; Accessed 4/14/2010.
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  • Medscape Reference provides information on this topic. Click on the link to view this information. You may need to register to view the medical textbook, but registration is free.
  • The Online Mendelian Inheritance in Man (OMIM) is an catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs.  Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Mucopolysaccharidosis type IIIA. Click on the link to view a sample search on this topic.

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