Why Stichting Muk exists

Muk is our cheerful, strong-willed and loving little girl. She has Sanfilippo type A (MPS IIIA), a rare, inherited and progressive metabolic disease that affects the brain. It can cause a child to gradually lose the skills they have learned.

The US FDA approved FAYUVI, formerly UX111, on 17 September 2026. It is a one-time gene therapy given through an infusion that helps the body produce the missing enzyme. Doctors assess whether FAYUVI is suitable for each child, including Muk.

Stichting Muk was founded to be ready if treatment becomes medically and practically possible for Muk. We also want to raise awareness of childhood dementia and help improve the chances of children with Sanfilippo.

Every day matters for Muk. With careful information, transparency and your support, we want to give her as much of a future as possible.

Our mission

Doing everything we responsibly can for Muk’s future

Making access to treatment possible

FAYUVI, formerly UX111, is approved in the United States. Whether and when treatment is medically suitable and available for Muk is still being assessed. We want to be ready to act as soon as treatment becomes possible.

The milestone of 1 million euros has been reached. The total cost of treatment, medical preparation, travel and accommodation is still unknown. That is why we are continuing to raise funds. As more becomes clear, the foundation will share the details as specifically as possible.

Care, medication and supportive therapies

Where this fits the foundation’s purposes and medical advice, funds may also be needed for care, medication, therapies and other support that contributes to Muk’s quality of life.

Raising awareness of childhood dementia

Childhood dementia is still little known. By sharing reliable information and Muk’s story, we want to encourage understanding, research and access to treatment. Greater awareness also means more support for other families living with Sanfilippo.

Our goal: to be ready when every day matters

Stichting Muk has reached the milestone of 1 million euros and is continuing to raise funds.

Donations are intended to make FAYUVI or another medically suitable treatment, and the journey around it, possible for Muk. If availability or costs change, the foundation will communicate openly about this. The funds remain under the foundation’s management within its purposes as set out in its statutes.

You can find more information in our frequently asked questions.

Two foundations, each with its own role

Stichting Muk tegen Kinderdementie focuses on Muk’s future. Stichting Sanfilippo Fonds has a broader purpose for children with Sanfilippo. They are separate foundations, each with its own board, records, bank account and purpose.

The ANBI status held since 30 October 2025 belongs to Stichting Sanfilippo Fonds (RSIN 868618834) and does not automatically apply to Stichting Muk. Any collaboration or contribution between the two foundations is decided separately, recorded and explained transparently.

Donate now give Muk a future