Hurler syndrome
Alternative names of Hurler syndrome
Alpha-L-iduronate deficiency (formerly gargoylism)
Infdormation about Hurler syndrome
Hurler syndrome is an inherited disease that belongs to a group
of diseases called mucopolysaccharidoses. Storage of abnormal quantities of this material
(mucopolysaccharide) in different body tissues is responsible for the symptoms and
appearance of the disease.
Causes, incidence, and risk factors for Hurler
syndrome
Hurler syndrome is inherited as an autosomal recessive trait.
The metabolic defect that causes Hurler syndrome is the body's inability to make an enzyme
called lysosomal alpha-L-iduronate.
Approximately 1 in 150,000 infants are affected. Newborn infants with this defect
appear normal at birth but, by the end of the first year, signs of impending problems
begin to develop. The children slowly develop coarse, thick, facial features, prominent
dark eyebrows, cloudy corneas, progressive stiffness, and obvious mental retardation.
The disease damages many organs including the heart and heart valves. In the early
onset form of the disease, death occurs in the early teens, often from the associated
heart disease.
Symptoms of Hurler syndrome
- Short stature
- Severe mental retardation
- Thick, coarse facial features with low nasal bridge
- Full lips with a thick, large tongue
- Cloudy corneas
- Increased body hair
- Umbilical hernia
- Deafness
- Stiffness (in joints)
- Shortness of breath
- Abnormal bones of spine and claw hand
Signs and tests of Hurler syndrome
- Hepatomegaly
- Splenomegaly
- Inguinal hernia
- Flared nostrils
- Epicanthal folds
- Enlarged tongue
- Retinal pigmentation
- Hip dislocation
- Vertebral wedging
- Kyphosis
- Heart murmurs
- Heart valve damage from thickening
Tests that may indicate the syndrome is present include:
- Increased excretion of dermatan sulfate and heparan sulfate in the urine
- Absence of lysosomal alpha-L-iduronidase (in cultured fibroblasts)
- Culture of cells from amniotic fluid obtained by amniocentesis for enzyme testing
(prenatal testing)
- Abnormal histologic staining of white blood cells called metachromasia
- X-ray of the skeleton
- X-ray of the spine
- X-ray of the chest
- ECG
Treatment of Hurler syndrome
There is no specific treatment for Hurler syndrome. Therapy must
address specific developing problems. Bone marrow transplantation may slow the disease
progression, but it is too early to know if it will be an effective treatment. Attempts at
enzyme replacement therapy have not been successful to date.
Expectations (prognosis)
Hurler syndrome is a disease with a poor prognosis. Children
with this disease have significant progressive physical and mental deficiencies. Death can
occur in late childhood, early adolescence, or
adulthood.
Complications of Hurler syndrome
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