Skip to content
How It Works
Explore
Resources Ask a Question
Who It's For
Patients
Decode results, prep for appointments, weigh options.
Caregivers & advocates
Carry the research load for someone you love.
Providers & clinicians
Resources for patients in your practice.
Log In Ask a Question
PubMed This is a summary of 17 peer-reviewed journal articles Updated
Cardiology

What is the Life Expectancy for MPS I (Hurler Syndrome)?

At a Glance

Life expectancy for MPS I depends on disease severity. Untreated severe MPS I (Hurler syndrome) is often fatal by age 10, but early stem cell transplants can extend survival into adulthood. Patients with milder forms using enzyme replacement therapy can achieve a near-normal lifespan.

In this answer

3 sections

01

Severe MPS I (Hurler Syndrome)

02

Attenuated MPS I (Hurler-Scheie and Scheie Syndromes)

03

Ongoing Care and the Journey Ahead

Hearing a diagnosis of Mucopolysaccharidosis type 1 (MPS I) often brings an immediate, terrifying question: What does this mean for the future? The most important thing to know right now is that the outlook for MPS I has changed dramatically in recent years. While life expectancy depends heavily on which form of the disease you or your child has and how quickly treatment begins, modern therapies have significantly extended survival and improved quality of life [1][2].

Because MPS I exists on a spectrum, the long-term outlook varies. Medical teams generally classify the condition into a severe form (Hurler syndrome) and attenuated, or milder, forms (Hurler-Scheie and Scheie syndromes) [3][4].

Severe MPS I (Hurler Syndrome)

For children diagnosed with the severe form of MPS I, early intervention is absolutely critical [5][6]. Without treatment, the disease progresses rapidly, and sadly, children with untreated Hurler syndrome typically do not survive past early childhood (often passing away before age 10) due to severe respiratory and heart complications [7][8].

However, Hematopoietic Stem Cell Transplantation (HSCT)—a procedure that replaces the blood-forming cells with healthy ones from a donor—has revolutionized care [9][10]. When performed early, ideally before the age of two, HSCT can slow the progression of the disease, stabilize brain function, and significantly extend a child’s life well into adulthood [5][8]. It is important to know that HSCT is a major, intensive medical procedure with significant risks that require careful consideration and a long hospital stay. Often, doctors will immediately start a child on Enzyme Replacement Therapy (ERT) as a temporary “bridge” to support their health and stabilize them while a transplant donor is found [2][9]. The long-term success of the transplant heavily depends on how early the procedure is done and how well brain function was preserved before treatment [8].

Attenuated MPS I (Hurler-Scheie and Scheie Syndromes)

The attenuated forms of MPS I progress more slowly and may be diagnosed in older children or adults. For these patients, the standard treatment is Enzyme Replacement Therapy (ERT), which provides the body with the missing enzyme it needs to break down complex sugars [11][2]. This is typically given through lifelong, weekly intravenous (IV) infusions.

With consistent ERT and specialized care, many individuals with attenuated MPS I live into their 30s, 40s, and beyond, sometimes achieving a near-normal life expectancy [1][12]. Because the disease still causes gradual wear on the body, an individual’s lifespan often depends on the extent of heart valve and lung involvement [13][1]. Early initiation of ERT can slow down this physical toll and protect these vital organs [14][5]. However, ERT does not cross the blood-brain barrier, meaning it effectively treats physical organ symptoms but cannot address neurological or central nervous system issues [2].

Ongoing Care and the Journey Ahead

Whether facing the severe or attenuated form, treatments like HSCT and ERT are not total cures. They do not reverse all damage, and even after successful treatment, patients will have a residual disease burden [8]. This means they may still face ongoing challenges, such as bone and joint issues (like hip dysplasia), heart valve changes, vision problems, and sleep apnea [15][16].

Because of this, lifelong monitoring by a team of medical specialists—including cardiologists, pulmonologists, orthopedists, and ophthalmologists—is essential [2][17]. Proactive, multidisciplinary care ensures that any emerging complications are treated swiftly, giving you or your child the best possible chance for a long, fulfilling life.

Common questions in this guide

What is the life expectancy for severe MPS I (Hurler syndrome) without treatment?
Without early medical intervention, severe MPS I progresses rapidly. Children with untreated Hurler syndrome typically do not survive past early childhood, often passing away before the age of 10 from respiratory and heart complications.
Can treatments extend the lifespan of a child with Hurler syndrome?
Yes. When performed early, preferably before age two, a hematopoietic stem cell transplant (HSCT) can slow disease progression, stabilize brain function, and extend life well into adulthood.
How long can someone live with attenuated MPS I?
With consistent enzyme replacement therapy (ERT) and proactive medical care, many individuals with milder forms of MPS I (Hurler-Scheie and Scheie syndromes) live into their 30s, 40s, and beyond, sometimes achieving a near-normal life expectancy.
Does enzyme replacement therapy treat brain function in MPS I?
No, enzyme replacement therapy does not cross the blood-brain barrier. This means it effectively treats physical symptoms in the organs, but it cannot prevent or treat neurological or central nervous system issues.
Why is lifelong monitoring necessary for people with MPS I?
Even with successful treatments like stem cell transplants or ERT, patients with MPS I carry a residual disease burden. Ongoing monitoring by specialists is essential to swiftly manage complications like bone and joint issues, heart valve changes, and sleep apnea.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on the specific genetic mutation and current symptoms, where does the diagnosis fall on the severe to attenuated spectrum?
  2. 2.How quickly can we begin treatments like Enzyme Replacement Therapy or evaluation for a stem cell transplant?
  3. 3.What baseline tests for heart, lung, and brain function need to be done right now to guide the treatment plan?
  4. 4.How will we monitor heart valves, vision, and respiratory health over time?
  5. 5.Can you connect us with a metabolic specialist or a care center experienced in long-term MPS I management?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

Related questions

Do MPS I Treatments Cure Bone & Eye Problems?How is MPS I Inherited? Genetics & Carrier RisksHow to Tell the Difference Between MPS I and JIAWhat Are the Anesthesia Risks for Patients With MPS I?What Causes a False Positive MPS I Newborn Screening?What Specialists Are Needed for MPS I Long-Term Care?Why Do Children With MPS I Get Carpal Tunnel Syndrome?Why is ERT Used Before Stem Cell Transplant in MPS I?

References

References (17)
  1. 1

    An uplifted destiny for mucopolysaccharidosis type I with heart valve involvement.

    Manna R, Graziani F, Lillo R, et al.

    Internal and emergency medicine 2021; (16(8)):2325-2326 doi:10.1007/s11739-021-02746-4.

    PMID: 33893975
  2. 2

    Clinical outcomes of exclusive enzyme therapy (laronidase) in a cohort of patients with mucopolysaccharidosis type I.

    Guffon N, Pettazzoni M, Pangaud N, et al.

    Orphanet journal of rare diseases 2025; doi:10.1186/s13023-025-04157-6.

    PMID: 41353341
  3. 3

    Identification of a novel compound heterozygous IDUA mutation underlies Mucopolysaccharidoses type I in a Chinese pedigree.

    Zhou YA, Li P, Zhang Y, et al.

    Molecular genetics & genomic medicine 2020; (8(1)):e1058 doi:10.1002/mgg3.1058.

    PMID: 31758674
  4. 4

    Heart valve disease in Hurler-Scheie syndrome.

    García Del Rey MDC, Castrodeza J, Pinto Á, et al.

    Cardiology journal 2022; (29(5)):875-877 doi:10.5603/CJ.a2022.0066.

    PMID: 35818796
  5. 5

    Mucopolysaccharidosis Type I Newborn Screening: Best Practices for Diagnosis and Management.

    Clarke LA, Atherton AM, Burton BK, et al.

    The Journal of pediatrics 2017; (182()):363-370 doi:10.1016/j.jpeds.2016.11.036.

    PMID: 27939258
  6. 6

    Long-term evolution of mucopolysaccharidosis type I in twins treated with enzyme replacement therapy plus hematopoietic stem cells transplantation.

    Carbajal-Rodríguez LM, Pérez-García M, Rodríguez-Herrera R, et al.

    Heliyon 2021; (7(8)):e07740 doi:10.1016/j.heliyon.2021.e07740.

    PMID: 34458603
  7. 7

    Early disease progression of Hurler syndrome.

    Kiely BT, Kohler JL, Coletti HY, et al.

    Orphanet journal of rare diseases 2017; (12(1)):32 doi:10.1186/s13023-017-0583-7.

    PMID: 28193245
  8. 8

    Long-term outcome of Hurler syndrome patients after hematopoietic cell transplantation: an international multicenter study.

    Aldenhoven M, Wynn RF, Orchard PJ, et al.

    Blood 2015; (125(13)):2164-72 doi:10.1182/blood-2014-11-608075.

    PMID: 25624320
  9. 9

    Mucopolysaccharidosis Type I: Current Treatments, Limitations, and Prospects for Improvement.

    Hampe CS, Wesley J, Lund TC, et al.

    Biomolecules 2021; (11(2)) doi:10.3390/biom11020189.

    PMID: 33572941
  10. 10

    Mucopolysaccharidosis Type I: The Importance of Early Diagnosis for Adequate Treatment.

    Diogo R, Diogo L, Serra R, et al.

    Cureus 2023; (15(12)):e50595 doi:10.7759/cureus.50595.

    PMID: 38222174
  11. 11

    Mucopolysaccharidosis Type I.

    Kubaski F, de Oliveira Poswar F, Michelin-Tirelli K, et al.

    Diagnostics (Basel, Switzerland) 2020; (10(3)) doi:10.3390/diagnostics10030161.

    PMID: 32188113
  12. 12

    12 year follow up of enzyme-replacement therapy in two siblings with attenuated mucopolysaccharidosis I: the important role of early treatment.

    Gabrielli O, Clarke LA, Ficcadenti A, et al.

    BMC medical genetics 2016; (17()):19 doi:10.1186/s12881-016-0284-4.

    PMID: 26965916
  13. 13

    Mucopolysaccharidoses Causing Valvular Heart Disease: Report and Review of Surgical Management.

    Encarnacion CO, Hang D, Earing M, Mitchell ME

    World journal for pediatric & congenital heart surgery 2020; (11(4)):NP22-NP24 doi:10.1177/2150135117690105.

    PMID: 28421916
  14. 14

    Early treatment with laronidase improves clinical outcomes in patients with attenuated MPS I: a retrospective case series analysis of nine sibships.

    Al-Sannaa NA, Bay L, Barbouth DS, et al.

    Orphanet journal of rare diseases 2015; (10()):131 doi:10.1186/s13023-015-0344-4.

    PMID: 26446585
  15. 15

    Progression of Hip Dysplasia in Mucopolysaccharidosis Type I Hurler After Successful Hematopoietic Stem Cell Transplantation.

    Langereis EJ, den Os MM, Breen C, et al.

    The Journal of bone and joint surgery. American volume 2016; (98(5)):386-95 doi:10.2106/JBJS.O.00601.

    PMID: 26935461
  16. 16

    Obstructive sleep apnea syndrome after hematopoietic stem cell transplantation in children with mucopolysaccharidosis type I.

    Moreau J, Brassier A, Amaddeo A, et al.

    Molecular genetics and metabolism 2015; (116(4)):275-80.

    PMID: 26602600
  17. 17

    Challenges in Diagnosing and Managing Hurler Syndrome: A Case Report.

    Achiatar LS, Hazoor HB, Adwani R, et al.

    Cureus 2024; (16(8)):e67056 doi:10.7759/cureus.67056.

    PMID: 39286678

This page is for informational purposes only and does not replace professional medical advice. Always consult your metabolic specialist or healthcare provider regarding your specific MPS I prognosis and long-term care plan.

Get notified when new evidence is published on Mucopolysaccharidosis type 1.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.