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Metabolic & Lysosomal

Mucopolysaccharidosis Type I (MPS I) Clinical Trials

Also called MPS I, Hurler Syndrome, Scheie Syndrome, Hurler-Scheie Compound

Mucopolysaccharidosis Type I results from mutations in the IDUA gene encoding alpha-L-iduronidase, leading to inability to break down heparan sulfate and dermatan sulfate. These glycosaminoglycans accumulate in lysosomes throughout the body, causing progressive cellular dysfunction.

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About Mucopolysaccharidosis Type I

Mucopolysaccharidosis Type I results from mutations in the IDUA gene encoding alpha-L-iduronidase, leading to inability to break down heparan sulfate and dermatan sulfate. These glycosaminoglycans accumulate in lysosomes throughout the body, causing progressive cellular dysfunction. The three clinical phenotypes reflect the degree of enzyme deficiency: severe Hurler form has minimal enzyme activity, Hurler-Scheie has intermediate activity, and Scheie has near-normal enzyme activity with limited tissue involvement. Disease manifestations reflect GAG accumulation in different tissues: skeletal tissue causes bone dysostosis, brain accumulation causes cognitive decline, connective tissue accumulation causes joint stiffness, and cardiac valve involvement can lead to heart disease.

Hurler syndrome, the most severe form, presents in early childhood with progressive coarse facial features, growth failure, developmental delay or regression, organomegaly, and progressive skeletal deformities. Cardiac involvement includes valve disease leading to heart failure. Respiratory involvement develops from upper airway narrowing and lung disease. Hearing loss is progressive. Intellectual disability becomes increasingly apparent in the second and third year of life. Without treatment, Hurler syndrome is life-limiting, with most patients dying by the second to third decade from cardiac or respiratory complications. Scheie and Hurler-Scheie forms progress more slowly and typically have normal or near-normal intelligence.

Common Symptoms of Mucopolysaccharidosis Type I

Recognizing the signs of Mucopolysaccharidosis Type I early can lead to faster diagnosis and better outcomes. Symptoms may vary in severity from person to person. If you or a loved one are experiencing any of the following, consider speaking with a specialist.

  • Coarse facial features with progressive changes
  • Growth deficiency and short stature
  • Developmental delay and intellectual disability in severe forms
  • Hepatosplenomegaly causing abdominal distension
  • Joint stiffness and skeletal abnormalities
  • Hearing loss and vision problems

Who Mucopolysaccharidosis Type I Affects

Hurler syndrome typically presents by age 2-3 years. Scheie syndrome may not manifest until school age or later. Hurler-Scheie intermediate form has onset in childhood. Affects males and females equally. Autosomal recessive inheritance. Occurs in all populations with variable prevalence.

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Help Paying for Mucopolysaccharidosis Type I Treatment

Charity funds and drugmaker programs for Mucopolysaccharidosis Type I, checked at the source. Pick your insurance to see what fits.

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Charity funds
  • From a charity · NORD RareCare
    MPS I (Hurler Syndrome) Medical Assistance fund
    Open

    Pays for: Medical and medication costs.

    The foundation says: “Accepting Applications”
  • From a charity · NORD RareCare
    MPS I (Hurler Syndrome) Premium Copay Assistance fund
    Open

    Pays for: Insurance premiums and copays.

    The foundation says: “Accepting Applications”
  • From a charity · The Assistance Fund
    MPS I - Hurler Syndrome (Hurler-Scheie, Scheie) fund
    Open

    Pays for: Copays, coinsurance, deductibles and other health-related expenses.

    The foundation says: “OPEN — Accepting New Patients. TAF is currently accepting new patient enrollments for this program.”
  • From a charity · National MPS Society
    Family Assistance Program fund
    Apply directly

    Pays for: Specialized equipment and medical aids not covered by insurance (requires insurance denial and 10% family copay), up to $3,000 per year.

    The foundation says: “Status not shown on page”
  • From a charity · National MPS Society
    Medical Travel Assistance Program fund
    Apply directly

    Pays for: Travel to out-of-town medical appointments more than 125 miles away (per year), up to $550 per year.

    The foundation says: “Status not shown on page”
  • From a charity · National MPS Society
    Journey Assistance Program fund
    Apply directly

    Pays for: Items that ease daily life (40% of purchase price), up to $500 per year.

    The foundation says: “Status not shown on page”
Status as each foundation showed it on September 28, 2026.

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Side Effect Explorer

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Genetic Testing

Genetic testing can confirm a diagnosis, guide treatment decisions, and identify family members who may be at risk.

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Trusted Mucopolysaccharidosis Type I Resources

Reputable organizations and medical references for learning more about Mucopolysaccharidosis Type I, including disease registries, foundation resources, and clinical guidelines.

Active Clinical Trials for Mucopolysaccharidosis Type I

Use this Mucopolysaccharidosis Type I clinical trial finder to see the 11 studies recruiting patients in the United States and worldwide, with eligibility criteria in plain English. These studies play a critical role in advancing care for metabolic & lysosomal conditions and may offer access to treatments not yet widely available. Each trial below is sourced directly from ClinicalTrials.gov, with eligibility criteria translated into plain English to help patients and caregivers evaluate whether a study may be a fit.

TrialsSite mapPipeline timelineMedication checker

Note: Trial recruitment statuses on ClinicalTrials.gov may not immediately reflect recent FDA decisions, sponsor announcements, or enrollment changes. Always confirm a trial's current status directly with the study coordinator before making plans.

11 active trials worldwide
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RECRUITINGPHASE1, PHASE2Recently updatedNCT07640984

A Phase I/II Trial of JR-446 in Mucopolysaccharidosis Type IIIB (MPS IIIB)

Intervention: JR-446

Sponsor: JCR Pharmaceuticals Co., Ltd.

This is a global, open-label, Phase I/II, interventional trial in participants younger than 6 years of age with Mucopolysaccharidosis Type IIIB (MPS IIIB), designed to assess the safety and tolerability of JR-446, determine its pharmacodynamic effects, and explore its potential t...

Ages up to 5 Years5 locations
Started Sep 2026Updated 1 week agoEst. Jun 2028 (~1y 9m)
RECRUITINGPHASE1Recently updatedNCT05682144

ISP-001: Sleeping Beauty Transposon-Engineered B Cells for MPS I

Intervention: Autologous Plasmablasts (B cells)

Sponsor: Immusoft of CA, Inc.

A first-in-human study using ISP-001 in patients with Mucopolysaccharidosis Type I Hurler-Scheie and Scheie.

Ages 10 Years+2 locations
Started Apr 2023Updated 2 months agoEst. Jun 2029 (~2y 8m)
RECRUITINGUpdated a few months agoNCT05619900

Registry of Patients Diagnosed With Lysosomal Storage Diseases

Intervention: There is no intervention

Sponsor: University of California, San Francisco

This is an international prospective and retrospective registry of patients with Lysosomal Storage Diseases (LSDs) to understand the natural history of the disease and the outcomes of fetal therapies, with the overall goal of improving the prenatal management of patients with LSDs.

Ages up to 64 Years1 location
Started May 2022Updated 5 months agoEst. May 2050 (~23y 8m)
RECRUITINGPHASE1No updates in a whileNCT04532047

PEARL (PrEnAtal Enzyme Replacement Therapy for Lysosomal Storage Disorders)

Intervention: Aldurazyme (laronidase)

Sponsor: University of California, San Francisco

For detailed information, please view our study website: https://pearltrial.ucsf.edu/

The investigators aims to determine the the maternal and fetal safety and feasibility of in utero fetal enzyme replacement therapy in fetuses with Lysosomal Storage Diseases.

Ages 18 Years – 50 Years1 location
Started Jul 2021Updated 6 months agoEst. Jul 2031 (~4y 10m)
RECRUITINGNo updates in a whileNCT06036693

MPS (RaDiCo Cohort) (RaDiCo-MPS)

Sponsor: Institut National de la Santé Et de la Recherche Médicale, France

The goal of this observational study is to characterize the epidemiology and natural history of MPS diseases by building a retrospective and prospective collection of extensive phenotypic data from French MPS patients.

Ages not specified23 locations
Started Dec 2017Updated 7 months agoEst. Dec 2026 (~3 months)
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Active trial locations7 cities in the US

Trial Pipeline

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Data from ClinicalTrials.gov, U.S. National Library of Medicine.
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Patient Communities

Connect with other Mucopolysaccharidosis Type I patients, caregivers, and advocacy groups across Facebook groups, Reddit communities, and YouTube channels. These patient communities offer peer support, shared experiences, caregiver resources, and real-time discussion about Mucopolysaccharidosis Type I treatments, clinical trial participation, and day-to-day disease management.

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Related Metabolic & Lysosomal Conditions

Other rare diseases in the metabolic & lysosomal category. Patients with Mucopolysaccharidosis Type I may find relevant research, shared treatment pathways, or overlapping clinical trials among these related conditions.

Companies Developing Mucopolysaccharidosis Type I Treatments

8 pharmaceutical companies have Mucopolysaccharidosis Type I in their rare disease portfolio

Frequently Asked Questions About Mucopolysaccharidosis Type I