What is Sanfilippo Syndrome?

Sanfilippo syndrome (MPS III) is a rare, progressive neurodegenerative disease often described as “childhood dementia.” There is no cure, and treatments at this time are only symptomatic — hearing aids for hearing loss, speech and occupational therapy, medication for seizures, and similar supportive care.

Sanfilippo affects nearly every aspect of a child’s development and, due to its progressive nature, slowly robs children of the skills they have worked so hard to develop. Children often present with a wide range of overlapping symptoms that require lifelong, multidisciplinary care.

How Sanfilippo Affects Children

• Autism & Behavioral Dysregulation — Most children with Sanfilippo are initially diagnosed with autism. They may have limited communication, social challenges, impulsivity, hyperactivity, and difficulty with transitions. As the disease progresses, behavioral challenges often intensify.
• Intellectual Disability & Cognitive Decline — As a neurological disorder, children present with developmental delays and over time experience progressive brain damage.
• Speech & Communication Impairment — Children often have delayed speech, limited expressive and receptive language, and may eventually lose previously acquired communication skills.
• Epilepsy & Neurological Complications — Seizures are common and often require ongoing neurological care, medication management, and emergency preparedness.
• Sensory Processing Challenges — Children may be sensory-seeking or sensory-avoidant, impacting behavior, sleep, and daily functioning.
• Hearing Loss — Progressive hearing issues can further limit communication and engagement.
• Vision Loss — Many children develop progressive vision impairment, further isolating them from their environment.
• Gastrointestinal Issues — Chronic diarrhea, constipation, and feeding challenges are common and significantly impact quality of life.
• Sleep Disturbances — Severe sleep disruption is one of the most exhausting aspects for families, often requiring constant overnight care.
• Mobility Decline — Over time, children may lose mobility and require physical support, adaptive equipment, and full-time care.
• Disease Progression & No Cure — Sanfilippo is ultimately fatal. Families live with constant urgency. There are currently no widely approved cures or disease-modifying treatments.