Hurler syndrome

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Low nasal bridge

Hurler syndrome is a rare, inherited disease of metabolism in which a person cannot break down long chains of sugar molecules called glycosaminoglycans (formerly called mucopolysaccharides).

Hurler syndrome belongs to a group of diseases called mucopolysaccharidoses, or MPS.

See also:

• MPS II (Hunter syndrome)
• MPS IV (Morquio syndrome)
• MPS III (Sanfilippo syndrome)
• MPS I S (Scheie syndrome)

Alpha-L-iduronate deficiency; Mucopolysaccharidosis type I; MPS I H

Persons with Hurler syndrome do not make a substance called lysosomal alpha-L-iduronidase. This substance, called an enzyme, helps break down long chains of sugar molecules called glycosaminoglycans (formerly called mucopolysaccharides). These molecules are found throughout the body, often in mucus and in fluid around the joints.

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Without the enzyme, glycosaminoglycans build up and damage organs, including the heart. Symptoms can range from mild to severe.

Hurler syndrome is inherited, which means that your parents must pass the disease on to you. Both parents need to pass down the faulty gene in order for you to develop Hurler syndrome.

Hurler syndrome is a type of mucopolysaccharidosis called MPS I. Hurler syndrome is the most severe type. It is categorized as MPS I H.

The other subtypes of MPS I are:

• MPS I H-S (Hurler-Scheie syndrome)
• MPS I S (Scheie syndrome)

Review Date: 04/15/2009
Reviewed By: Chad Haldeman-Englert, MD, Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).