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. Alpha-L-iduronate deficiency;
Mucopolysaccharidosis type I; MPS I H Causes, incidence, and
risk factors 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. 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.