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Hurler syndrome (severe MPS I)

Hurler syndrome.Clarity for what comes next.

Carefully governed information and trusted signposting for families, carers and professionals.

Understand Hurler syndrome
Newly diagnosed? Start here
Published by MPS Bio

Choose the right starting point

Four routes — every route is also in the menu.

Route 01I want to understand Hurler syndromePlain-language answerRoute 02Someone has recently been diagnosedThe first steps, in orderRoute 03I need help or supportSignposting near youRoute 04I am a healthcare professionalGoverned summaries

What is Hurler syndrome?

General information. Not a diagnosis, and not medical advice.

Hurler syndrome is the severe form of mucopolysaccharidosis type I — MPS I — a rare inherited lysosomal storage disorder.

Reduced activity of a single enzyme means the body cannot fully break down certain complex sugars. They accumulate inside cells over time and can affect several body systems. Because change can be progressive, early assessment by a specialist metabolic team matters — it establishes what is happening and what the options are.

Continue to the detailed explanation →

Also calledSevere MPS I · MPS I-H
InheritanceAutosomal recessive
Enzyme involvedAlpha-L-iduronidase (IDUA)

What happens after diagnosis?

A general shape of the pathway. Your team decides the detail with you.

  1. Stage 01

    Specialist assessment

    A metabolic team confirms the picture and establishes a baseline across the systems they monitor.

  2. Stage 02

    Treatment discussions

    Options, timing and trade-offs are discussed with you. Nothing here replaces that conversation.

  3. Stage 03

    Multidisciplinary care

    Several specialties work together. Understanding who does what makes appointments easier to use.

  4. Stage 04

    Practical support

    Everyday help — school, work, travel, benefits, respite — and the organisations that provide it.

  5. Stage 05

    Continuing review

    Regular reassessment. Plans change as circumstances change, and that is expected.

Treatment and care

Three registers, kept deliberately separate.

General information

What the established approaches are, and how specialist teams tend to think about them.

  • Enzyme replacement therapy
  • Haematopoietic stem cell transplant
  • Supportive and symptom care
  • Long-term monitoring

Questions to discuss with your team

Written to be taken into an appointment, not answered here.

  • What is being monitored, and how often?
  • What would change the current plan?
  • Who coordinates between the specialties?
  • What should we watch for between visits?

Evidence boundaries

Where evidence is strong, where it is still developing, and where individual circumstances decide. We say so when something is uncertain, and we do not fill gaps with confidence we do not have.

How we govern this

Find support

Established MPS organisations, specialist centres and family networks — in the UK and internationally.

MPS Bio provides information, signposting and referral guidance. It does not fundraise or campaign, and it does not replace healthcare services, emergency care, specialist clinicians or established MPS organisations.

National MPS societies

Country-level organisations for families and carers.

Specialist metabolic centres

Where assessment and long-term care are coordinated.

Family and community networks

Peer contact, practical help and local groups.

International federations

Cross-border information and research links.

Ask us where to start

Important questions

Answers first. Nothing is hidden behind a click.

Is Hurler syndrome the same as MPS I?

It is the severe form of MPS I. Attenuated forms of MPS I are described separately, because the course and the decisions differ.

How is it diagnosed?

Through specialist assessment, which normally includes enzyme and genetic testing arranged by a metabolic team.

Is it inherited?

Yes. It is autosomal recessive, which is why genetic counselling is usually offered to families.

Can it be treated?

There are established approaches. What is appropriate for one person is decided with a specialist team, not from a website.

Where should we start today?

With one of the four routes above, then with your specialist team. If you are not sure, contact us and we will point you to the right place.

Trust and evidence

How this information is governed

Clinical wording across this website has been reviewed and approved for publication. Each page states its scope, evidence boundaries and review status.

Clinical wording approved

The current website wording was approved for publication by the Clinical approver role for MPS Bio on 23 August 2026.

Clinical wording statusApproved for publication
Approval recorded23 August 2026
Review cycleWithin twelve months of publication, or sooner if guidance changes
Approval accountabilityClinical approver role for MPS Bio
UncertaintyMarked in place, not omitted
PublisherMPS Bio — owner, publisher and data controller

We publish the review process, approval role and sources—not the names of appointed individuals. Editorial responsibility sits with MPS Bio as publisher.

Contact

If you are not sure where to start, ask us.

You can contact MPS Bio for information and signposting. Enquiries are normally answered within two working days, and we can suggest appropriate organisations in the UK or elsewhere.

Contact MPS BioHow enquiries are handled
This is not an emergency service

If someone needs urgent help, contact your clinical team or your local emergency services.