Hurler syndrome is a rare, inherited disease of
Hurler syndrome belongs to a group of diseases called mucopolysaccharidoses, or MPS.
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
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. If both parents carry the defective gene related to this condition, each of their children has a 25% chance of developing the disease.
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)
Symptoms of Hurler syndrome most often appear between ages 3 and 8. Infants with severe Hurler syndrome appear normal at birth. Facial symptoms may become more noticeable during the first 2 years of life.
- Abnormal bones in the spine
- Claw hand
Cloudy corneas Deafness
- Halted growth
- Heart valve problems
- Joint disease, including stiffness
Intellectual disabilitythat gets worse over time
- Thick, coarse facial features with
low nasal bridge
Exams and Tests
Genetic testing for changes (mutations) to the alpha-L-iduronidase (IDUA) gene
Urine tests for extra mucopolysaccharides
X-ray of the spine
Enzyme replacement therapy for Hurler syndrome adds a working form of the missing enzyme to the body. The medication, called laronidase (Aldurazyme), is given through a vein (intravenously). Talk to your doctor for more information.
Other treatments depend on the organs that are affected.
For more information and support, contact one of the following organizations:
- The National MPS Society —
- Canadian Society for MPS and Related Diseases —
- Society for MPS Diseases —
Hurler syndrome is a disease with a poor outlook. Children with this disease develop nervous system problems, and can die young.
When to Contact a Medical Professional
Call your health care provider if:
You have a family history of Hurler syndrome and are considering having children
Your child begins to show symptoms of Hurler syndrome
Experts recommend genetic counseling and testing for couples with a family history of Hurler syndrome who are considering having children. Prenatal testing is available.