MPS I (Hurler, Hurler-Scheie, Scheie syndrome)
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Overview
MPS I is a mucopolysaccharide disease also called Hurler, Hurler-Scheie and Scheie syndrome. Hurler takes its name from Gertrude Hurler, the doctor who described a boy and girl with the condition in 1919. In 1962, Dr. Scheie, a consultant ophthalmologist, wrote about patients who were more mildly affected. Individuals who do not fit the severe or mild ends of the disease were said to have Hurler/Scheie.
The specific disease names have been replaced with the designations attenuated (diminished severity) and severe MPS I. MPS I has a wide range of symptoms that vary in severity and can be managed and treated with enzyme replacement therapies. There is no cure for MPS I.
Severe MPS I occurs in approximately 1 in 100,000 newborns. Attenuated MPS I is less common and occurs in about 1 in 500,000 newborns.
Understanding the Cause of MPS and ML
Mucopolysaccharides are chains of sugar molecules used to build connective tissues in the body.
“muco” refers to the thick jelly-like consistency of the molecules
“poly” means many
“saccharide” is a general term for a sugar molecule
The body constantly replaces used materials and breaks them down for disposal. MPS I patients are missing the enzyme alpha-L-iduronidase, which is essential in breaking down the mucopolysaccharides dermatan sulfate and heparan sulfate. These materials remain stored in the body’s cells, causing progressive damage. Babies may show little sign of the disease, but as cells sustain damage, symptoms start to appear.
Understanding the Inheritance of the Disease
MPS I (Hurler-Scheie syndrome ) is caused by a recessive gene. There is a one in four chance with every pregnancy that the child will inherit the variant gene from each carrier parent and will be affected with the disease. There is a two in three chance that unaffected brothers and sisters of children with MPS I will be carriers.
Identifying the Type of MPS or ML Your Child Has
MPS I (Hurler-Scheie) is a continuum of severity based upon the symptoms, ranging from severe to attenuated. There is a great deal of variability of symptoms among individuals with MPS I, often making the specific designation difficult. Generally, severe MPS I will present within the first year of life while less severe (attenuated) forms present during childhood. Although individuals with attenuated MPS I have normal intelligence, they may have a variety of symptoms that can range from mild to severe.
Common Questions
What are the differences in Hurler, Hurler-Scheie, and Scheie syndromes?
Hurler Syndrome (MPS I-H)
This is the most severe form. Symptoms often appear in the first year of life and include developmental delays, vision and hearing problems, heart issues, and changes in facial features and bone structure.
Hurler-Scheie Syndrome (MPS I-H/S)
This is a moderate form. Symptoms may appear between ages 3 and 8. Children often have normal cognitive and learning abilities, but may face physical challenges like joint stiffness, vision or hearing loss, and heart problems.
Scheie Syndrome (MPS I-S)
This is the mildest form. Symptoms can show up later in childhood, or even adulthood. Cognitive ability is not typically affected, but people may have joint pain, heart valve issues, or cloudy vision.
What treatments are on the horizon?
For individuals and families living with Hurler syndrome (MPS I), treatment has traditionally focused on enzyme replacement therapy (ERT) and stem cell transplant. These therapies can be life-changing, especially when started early, but they don’t address all symptoms—particularly those affecting the brain and bones.
Researchers are now working to change that. New therapies in development aim to go beyond symptom management, offering the potential for longer-lasting and more complete treatment.
How do we know what kind of treatment is appropriate?
Deciding on a treatment path for your child with Hurler syndrome is deeply personal—there is no one-size-fits-all approach, and the right decision depends on many factors, including age, overall health, symptoms, and timing of diagnosis.
Options like enzyme replacement therapy (ERT) and stem cell transplant have different goals, risks, and benefits, so it’s important to work closely with a team of specialists who understand MPS I and can help guide you.
Essais cliniques
Clinical trials are research studies that determine whether treatments or devices are safe for humans. These studies also look for effective medical approaches for specific conditions and help provide reliable data for patients, researchers and doctors.
Clinical trials are conducted on small groups to determine whether a drug or procedure causes negative reactions or unsatisfactory side effects.
ERT
Enzyme replacement therapy (ERT) uses an intravenous solution (IV) to replace a deficient or missing enzyme in the body. ERT does not cure the disease but slows its progress by increasing the amount of missing enzyme in the body.
Aldurazyme™ (laronidase), administered once weekly, is approved in more than 60 countries worldwide, including the United States and across Europe for long-term enzyme replacement therapy in patients with a confirmed diagnosis of MPS I, to treat the non-neurological manifestations of the disease.
Visit aldurazyme.com or contact Sanofi Genzyme at 800-745-4447 for more information.
Hematopoietic Stem Cell Transplantation (HSCT)
HSCT is a blood stem cell transplant. Possible sources of blood stem cells include bone marrow, peripheral blood and umbilical cord blood.
Traitements émergents
Pharmaceutical companies, medical researchers and clinicians are constantly working on emerging treatments for MPS. The following companies are working on therapies for MPS I.
Need Support? We’re Here for You
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