Learn About Mucopolysaccharidosis Type 3A

What is the definition of Mucopolysaccharidosis Type 3A?

Mucopolysaccharidosis type III (MPS III) is a rare disease in which the body is missing or does not have enough of certain enzymes needed to break down long chains of sugar molecules. These chains of molecules are called glycosaminoglycans (formerly called mucopolysaccharides). As a result, the molecules build up in different parts of the body and cause various health problems.

The condition belongs to a group of diseases called mucopolysaccharidoses (MPSs). MPS II is also known as Sanfilippo syndrome.

There are several other types of MPSs, including:

  • MPS I (Hurler syndrome; Hurler-Scheie syndrome; Scheie syndrome)
  • MPS II (Hunter syndrome)
  • MPS IV (Morquio syndrome)
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What are the alternative names for Mucopolysaccharidosis Type 3A?

MPS III; Sanfilippo syndrome; MPS IIIA; MPS IIIB; MPS IIIC; MPS IIID; Lysosomal storage disease - mucopolysaccharidosis type III

What are the causes of Mucopolysaccharidosis Type 3A?

MPS III is an inherited disorder. This means it is passed down through families. If both parents carry a nonworking copy of a gene related to this condition, each of their children has a 25% (1 in 4) chance of developing the disease. This is called an autosomal recessive trait.

MPS III occurs when the enzymes needed to break down the heparan sulfate sugar chain are missing or defective.

There are four main types of MPS III. The type a person has depends on which enzyme is affected.

  • Type A is caused by a defect in the SGSH gene and is the most severe form. People with this type do not have a normal form of the enzyme called heparan N-sulfatase.
  • Type B is caused by a defect in the NAGLU gene. People with this type are missing or do not produce enough alpha-N-acetylglucosaminidase.
  • Type C is caused by a defect in the HGSNAT gene. People with this type are missing or do not produce enough acetyl-CoA:alpha-glucosaminide N-acetyltransferase.
  • Type D is caused by a defect in the GNS gene. People with this type are missing or do not produce enough N-acetylglucosamine 6-sulfatase.
What are the symptoms of Mucopolysaccharidosis Type 3A?

Symptoms often appear after the first year of life. A decline in learning ability typically occurs between ages 2 and 6. The child may have normal growth during the first few years, but final height is below average. Delayed development is followed by worsening mental status.

Other symptoms may include:

  • Behavioral problems, including hyperactivity
  • Coarse facial features with heavy eyebrows that meet in the middle of the face above the nose
  • Chronic diarrhea
  • Enlarged liver and spleen
  • Sleep difficulties
  • Stiff joints that may not extend fully
  • Vision problems and hearing loss
  • Walking problems
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What are the current treatments for Mucopolysaccharidosis Type 3A?

Treatment of MPS III is aimed at managing the symptoms. There is no specific treatment for this disease. New research is under development for gene therapy and enzyme replacement.

Who are the top Mucopolysaccharidosis Type 3A Local Doctors?
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Highly rated in
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University Of Manchester

Stem Cell And Neuropathies, Division Of Cell Matrix Biology & Regenerative Medicine 
Manchester, ENG, GB 

Brian Bigger practices in Manchester, United Kingdom. Bigger is rated as an Elite expert by MediFind in the treatment of Mucopolysaccharidosis Type 3A. He is also highly rated in 13 other conditions, according to our data. His top areas of expertise are Mucopolysaccharidoses, Mucopolysaccharidosis Type 3, Mucopolysaccharidosis Type 3A, and Mucopolysaccharidosis Type 3B.

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Highly rated in
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University Of Amsterdam

Laboratory Genetic Metabolic Diseases, And Metabolism Institute 
Amsterdam, NH, NL 

Frits Wijburg practices in Amsterdam, Netherlands. Wijburg is rated as an Elite expert by MediFind in the treatment of Mucopolysaccharidosis Type 3A. They are also highly rated in 34 other conditions, according to our data. Their top areas of expertise are Mucopolysaccharidosis Type 3A, Mucopolysaccharidosis Type 3, Mucopolysaccharidoses, and Very Long-Chain Acyl-Coa Dehydrogenase Deficiency.

 
 
 
 
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Highly rated in
3
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University Of Manchester

Brain Tumor Research Group, Stem Cell And Neurotherapies Laboratory, Division Of Cell Matrix Biology And Regenerative Medicine 
Manchester, ENG, GB 

Stuart Ellison practices in Manchester, United Kingdom. Ellison is rated as an Elite expert by MediFind in the treatment of Mucopolysaccharidosis Type 3A. He is also highly rated in 3 other conditions, according to our data. His top areas of expertise are Mucopolysaccharidosis Type 3A, Mucopolysaccharidosis Type 3, Mucopolysaccharidoses, and Mucopolysaccharidosis Type 3B.

What are the support groups for Mucopolysaccharidosis Type 3A?

More information and support for people with MPS III and their families can be found at:

  • National Organization for Rare Disorders -- rarediseases.org/rare-diseases/mucopolysaccharidosis-type-iii/
  • NIH Genetic and Rare Diseases Information Center -- rarediseases.info.nih.gov/diseases/3807/mucopolysaccharidosis-type-iii
  • Team Sanfilippo Foundation -- teamsanfilippo.org/
What is the outlook (prognosis) for Mucopolysaccharidosis Type 3A?

MPS III causes significant nervous system symptoms, including severe intellectual disability. Most people with MPS III live into their teenage years. Some live longer, while others with severe forms die at an earlier age. Symptoms are most severe in people with type A.

What are the possible complications of Mucopolysaccharidosis Type 3A?

These complications can occur:

  • Blindness
  • Inability to care for self
  • Intellectual disability
  • Nerve damage that slowly gets worse and eventually requires wheelchair use
  • Seizures
When should I contact a medical professional for Mucopolysaccharidosis Type 3A?

Call your child's provider if your child does not seem to be growing or developing normally.

See your provider if you plan to have children and you have a family history of MPS III.

How do I prevent Mucopolysaccharidosis Type 3A?

Genetic counseling is recommended for couples who want to have children and who have a family history of MPS III. Prenatal testing is available.

What are the latest Mucopolysaccharidosis Type 3A Clinical Trials?
A Phase I-II, Study of Autologous CD34+ Haematopoietic Stem Cells Transduced ex Vivo With CD11b Lentiviral Vector Encoding for Human SGSH in Patients With Mucopolysaccharidosis Type IIIA (MPS IIIa, Sanfilippo Syndrome Type A)
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Prospective, Natural History Study of Patients With Sanfilippo Syndrome Type A (MPS IIIA)
What are the Latest Advances for Mucopolysaccharidosis Type 3A?
Intrathecal heparan-N-sulfatase in patients with Sanfilippo syndrome type A: A phase IIb randomized trial.
Cases of inborn errors of metabolism diagnosed in children with autism.
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MUCOPOLYSACARIDOSIS TYPE IIIB MISDIAGNOSED AS AN AUTISTIC SPECTRUM DISORDER: A CASE REPORT AND LITERATURE REVIEW.
Who are the sources who wrote this article ?

Published Date: May 02, 2021
Published By: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

What are the references for this article ?

Pearse Y, Iacovino M. A cure for Sanfilippo syndrome? A summary of current therapeutic approaches and their promise. Med Res Arch. 2020;8(2):10. PMID: 32733997 pubmed.ncbi.nlm.nih.gov/32733997/.

Pyeritz RE. Inherited diseases of connective tissue. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 244.

Spranger JW. Mucopolysaccharidoses. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 107.

Turnpenny PD, Ellard S, Cleaver R. Inborn errors of metabolism. In: Turnpenny PD, Ellard S, Cleaver R, eds. Emery's Elements of Medical Genetics and Genomics. 16th ed. Philadelphia, PA: Elsevier; 2022:chap 18.