Newly diagnosed with Hurler syndrome
Hearing that your child has Hurler syndrome (severe MPS I, MPS I-H) is overwhelming. You may feel shocked, frightened, confused or numb – sometimes all at once. It can be hard to take in medical information while you are trying to cope emotionally and look after your family.
This page is for parents, carers and relatives at the very start of the journey. It explains, in clear language, what Hurler syndrome is, what usually happens in the first months after diagnosis, and practical steps you can take right now.
It’s normal to feel overwhelmed
Common reactions in the first days and weeks include:
- Shock and disbelief – “This can’t be happening”
- Guilt or self-blame – even though nothing you did caused this condition
- Anger, sadness or fear about the future
- Difficulty sleeping or concentrating
- Feeling pulled between hospital, work and caring for other children
You do not have to be “strong” all the time.
Many parents find it helpful to:
- Have a trusted friend or relative come to appointments to take notes
- Ask the team to repeat explanations and provide written information
- Speak with a psychologist, counsellor, or peer parent if available
What Hurler syndrome meansYour team will gradually explain the science in more detail, but in simple terms:
- Hurler syndrome is the severe form of MPS I, a rare inherited condition.
- Children are born with a very low level of an enzyme called alpha-L-iduronidase (IDUA).
- Without enough IDUA, certain natural sugars (glycosaminoglycans, or GAGs) build up in cells and tissues.
Over time, this affects many parts of the body: growth, bones, heart, lungs, brain, eyes, ears and more.
Hurler syndrome is genetic, meaning it is caused by changes in a gene passed down from parents. Nothing you did during pregnancy or early life caused this.
Key Facts
The first steps in the care pathway
Although details differ between countries and centres, many families go through similar early steps.
Confirming the diagnosis
- Blood and urine tests
- Genetic testing for the IDUA gene
- Sometimes enzyme activity tests
Baseline assessments
- Heart scan (echocardiogram)
- Breathing and sleep assessments
- X-rays and scans of bones and spine
- Eye and hearing tests
- Developmental assessment
Talking about treatment options
- Discussion of HSCT
- Enzyme replacement therapy (ERT)
- Supportive and surgical treatments
Planning next steps
- Choosing the lead care centre
- Scheduling treatments and follow-ups
HSCT, ERT and supportive care – in simple terms
Your doctors may talk about:
Haematopoietic stem cell transplantation (HSCT)
- A major treatment that replaces your child’s bone marrow with cells from a donor.
- These donor cells can make the missing enzyme and help protect the brain and many organs.
Usually considered the standard treatment for children with severe Hurler syndrome when diagnosed early and medically fit.
Enzyme replacement therapy (ERT)
- A weekly intravenous infusion of the missing enzyme (laronidase).
Helps many body organs, but does not adequately reach the brain, so it is usually used alongside HSCT in severe Hurler syndrome, or as long-term treatment in milder forms or in children who cannot have HSCT.
Enzyme replacement therapy (ERT)
- Operations and therapies to help the heart, lungs, bones, ears, eyes, teeth, movement and pain.
These are needed before, during and after HSCT or ERT.
On this page you don’t need to decide anything; the aim is just to give you a road map of what the terms mean.