Symptoms:

Juvenile form (early-onset, severe form):

• Aggressive behavior
• Hyperactivity
• Mental function gets worse over time
• Severe mental retardation
• Spasticity

Late (mild) form:

• Mild to no mental deficiency

Both forms:

• Carpal tunnel syndrome
• Coarse features of the face
• Deafness (gets worse over time)
• Increased hair (hypertrichosis)
• Joint stiffness
• Large head (macrocephaly)

Signs and tests:

Signs of the disorder include:

• Abnormal retina (back of the eye)
• Decreased iduronate sulfatase enzyme in blood serum or cells
• Heart murmur and leaky heart valves
• Enlarged liver (hepatomegaly)
• Enlarged spleen (splenomegaly)
• Inguinal hernia
• Joint contractures
• Spasticity

Tests may include:

• Enzyme study
• Genetic testing for change (mutation) in the iduronate sulfatase gene
• Urine test for heparan sulfate and dermatan sulfate