About Sanfilippo

Sanfilippo Syndrome (also known as MPS III) is a progressive and fatal disease affecting 1 in 70,000 children. It is a genetic condition that affects the metabolism and results in severe damages to the Central Nervous System.

Individuals affected by Sanfilippo lack an enzyme necessary to break down long chains of sugar molecules. As these molecules accumulate in the cells, they start causing cellular dysfunctions, particularly in the brain, causing affected children to lose memory and forget how to walk, talk, and feed themselves. The life expectancy of diagnosed children is 10-20 years.

Learn more at the Cure Sanfilippo Foundation

"We cheer on our children for every little milestone, every gain. How does a parent respond when it's going in the other direction?" 

- Cara O'Neill (mother of Eliza O'Neill)


  • Speech delay
  • Recurrent ear/sinus infections
  • Large head size
  • Diarrhea/chronic loose stool
  • Poor sleep
  • Speech/developmental delays
  • "Autistic" behaviors
  • Hyperactivity


  • Progressive intellectual disability
  • Seizures
  • Enlarged liver/spleen
  • Hearing loss (may occur earlier)
  • Loss of mobility
  • Loss of ability to eat by mouth