What are the signs and symptoms of MPS I?

MPS I has a wide range of symptoms, and people may experience different degrees of disease progression. Because the signs and symptoms are variable, it affects each individual differently. The list below provides an overview of the signs and symptoms that may occur in individuals with various severities of MPS I.  


Stiffened Joints 
Stiffness of joints may cause pain and limited range of movement and may create challenges with dressing and other activities. 

Skeletal Problems 
Skeletal problems can include problems with growth and bone formation, including abnormally shaped bones. The spine can also be affected, including spinal deformities such as scoliosis and poorly formed spine. 

Carpal Tunnel Syndrome 
A condition that causes pain, numbness, and tingling in the hand and arm. This may cause nerve damage and challenges grasping objects.

Heart Disease 
Some types of heart problems that occur in people living with Hurler include: weakened heart muscle, stiffened and scarred heart, and coronary artery disease. Patients living with MPS I disease also may develop problems with their heart valves. 

Upper Airway Infections 
Upper airway infections include bacterial infections that occur in the middle area of the ear and sinuses. 

Obstructive Sleep Apnea
Obstructive sleep apnea is a potentially serious sleep disorder that causes the muscles in the throat to relax and block the airway during sleep, which causes breathing to repeatedly stop and start. 

Corneal Clouding 
The cornea can become cloudy, which can limit vision. 

Spinal Cord Compression 
Spinal cord compression occurs when fluid or tissues press against the spinal cord, which can cause numbness, pain, and weakness. 

Enlarged Liver and Spleen 

Hernia 
In people with MPS I, a hernia which is a bulge in the abdomen or groin, can occur. Hernia can often be harmless and pain-free, but at times it can bring discomfort and pain. 

Hearing Loss 

Delayed Cognitive Development 

Coarse Facial Features 
People living with MPS I can have large heads, flat faces, shallow eye sockets, large tongue, and broad, short noses. 

Fluid on the Brain (Communicating Hydrocephalus) 
A condition in which the clear fluid that surrounds the brain and spinal cord builds up and causes pressure on the brain. 

Abnormally Shaped Teeth 
The outer layer of the teeth, known as the enamel, can be fragile and there can be poor teeth formation. 

Life expectancy

Life expectancy varies significantly for people with MPS I. This depends on many factors, such as where they are on the spectrum of disease severity, and management of its signs and symptoms. The affected individuals on the Scheie side of the spectrum can have a lifespan into adulthood. Some individuals who are more severely affected (those with what was historically called Hurler-Scheie disease) may die before becoming teenagers, while others may live to be adults. The most severely affected children (those with what was historically known as Hurler) rarely live more than 10 years.

Did You Know?

Genetic counselors are health professionals who are trained to help families understand genetic disorders such as MPS I disease. A genetic counselor can help you determine if you are a carrier of a gene defect that causes MPS I and can provide valuable information and support for family planning.
To learn more, click here.