Hurler’s disease is a rare hereditary disease of metabolism characterized by severe abnormalities in the development of skeletal cartilage and bone, often resulting in dwarfism and limb deformities. Individuals with Hurler’s disease do not make a substance called lysosomal alpha-L-iduronidase, an enzyme that helps break down long chains of sugar molecules called glycosaminoglycans. These molecules are found throughout the body, particularly in fluid around the joints.
Hurler’s disease belongs to a group of diseases called mucopolysaccharidoses (MPS). Hurler’s disease is the most severe type and is categorized as MPS I H. Other forms of MPS include:
- MPS I S - Scheie Syndrome
- MPS II - Hunter Syndrome
- MPS III - Sanfilippo Syndrome
- MPS IV - Morquio Syndrome
Hurler’s disease is inherited recessively and linked to the IDUA gene, which codes for the lysosomal alpha-L-iduronidase enzyme. Parents of affected individuals are typically genetic carriers of the disease; they often do not display any symptoms themselves. The disease is quite rare, occurring in 1 out of 100,000 individuals.
Individuals with Hurler’s disease will present with symptoms between the ages of 3 and 8. Even those with severe Hurler’s disease often appear normal at birth. The first sign of the disease is usually the development of facial symptoms within the first two years of life. Symptoms of Hurler’s disease include:
- Joint disease and limb deformities
- Claw hand deformity
- Spinal deformities
- Short stature
- Cloudy corneas
- Heart defects
- Thick, coarse facial features
- Developmental delay
At the Paley Institute we address the orthopedic difficulties of Hurler’s disease. In particular, we correct the limb deformities with reconstructive surgery.